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General Physics 1 (PHYC-121) WEEK 1 LEARNING ACTIVITY 1 SHORT QUIZ 1 Question 1 A furlong is a distance of 180 yar

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General Physics 1 (PHYC-121)

WEEK 1 LEARNING ACTIVITY 1 SHORT QUIZ 1 Question 1

A furlong is a distance of 180 yards. A fortnight is a time period of two weeks. A race horse is running at a speed of 7 yards per second. What is his speed in furlongs per fortnight? c. 47,040 furlongs/fortnight Question 2

Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 25 and 53 cm, how many significant figures will result if you only use the part of the meter stick between the 3- and 85-cm positions? d. 4 Question 3

Vector A is 5 m long and vector B is 12 m long. The length of the sum of the vectors must be: a. some value from 7 m to 17 m. Question 4

A train slowly climbs a 450-m mountain track which is at an angle of 10.0° with respect to the horizontal. How much altitude does it gain? d. 78.1 m

Question 5

How long has it been that scientists have accepted that the nucleus of the atom consists of neutrons and protons? Think of your answers in terms of order of magnitude. c. about a century Question 6

A triangle has sides of lengths 14 cm and 50 cm. If the triangle is a right triangle, which of the following could be the length of the third side? d. 48 cm Question 7

If θ and φ are each first quadrant angles, which of the following must be true if sin θ = cos φ? d. θ + φ = 90° Question 8

On planet Q the standard unit of volume is called the guppy. Space travelers from Earth have determined that one liter = 36.6 guppies. How many guppies are in 100 liters? e. 3,660 guppies Question 9

Suppose an equation relating position, x, to time, t, is given by x = b t3 + c t4, where b and c are constants. The dimensions of b and c are respectively: c. L/T3, L/T4. Question 10

Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: d. 196

? [15.0 X 5.6 X 2.33]

WEEK 2 LEARNING ACTIVITY 2 Question 1

2.2 What is Motion? A car is initially moving at 30 m/s east and a little while later it is moving at 10 m/s north. Which of the following best describes the orientation of the average acceleration during this time interval? a. north of west Question 2

Jeff throws a ball straight up. For which situation is the vertical velocity zero? c. at the top Question 3

2.4 Newton's Laws of Motion An astronaut applies a force of 500 N to an asteroid, and it accelerates at 3.00 m/s2. What is the asteroid's mass? b. 167 kg Question 4

Consider the magnitude of the average speed, ⱽspeed,mag, and the magnitude of the average velocity, ⱽvelocity,mag, for the same trip. Which of the following is always true? ⱽavg,speed,mag ≥ ⱽavg,velocity,mag Question 5

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time) d. at

SHORT QUIZ 2 Question 1

An object is dropped from a height. Once it is moving, which of the following statements is true, at least at one point? a. Its velocity is never equal to its acceleration. Question 2

A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the acceleration of the ball is zero. We know that at t = 5 s, a. the velocity of the ball is not changing. Question 3

2.2 What is Motion? A jogger runs halfway around a circular path with a radius of 70 m. What, respectively, are the magnitude of the displacement and the distance jogged? d. 140 m, 220 m Question 4

A railroad train travels forward along a straight track at 70 m/s for 2,000 m and then travels at 50 m/s for the next 2,000 m. What is the average velocity? a. 58.3 m/s Question 5

A 50-g ball traveling at 27.0 m/s is bounced off a brick wall and rebounds at 21.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.00 ms, what is the average acceleration of the ball during this time interval? b. 16,000 m/s2 Question 6

A cheetah can maintain its maximum speed of 95 km/hr for 27.0 seconds. What minimum distance must a gazelle running 78 km/hr be ahead of the cheetah to escape? b. 127 m

Question 7

Which of the following is not a vector quantity? c. temperature Question 8

2.2 What is Motion? A truck moves 70 m west, then moves 120 m east, and finally moves west again a distance of 90 m. If east is chosen as the positive direction, what is the truck's resultant displacement? d. − 40 m Question 9

The distance of the Earth from the sun is 93 000 000 miles. If there are 3.15 × 107 s in one year, find the speed of the Earth in its orbit about the sun. c. 18.6 miles/s Question 10

A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average velocity is: b. not given.

WEEK 3 LEARNING ACTIVITY 3 Question 1

A quarterback takes the ball from the line of scrimmage, runs backward for 10 yards, then sideways parallel to the line of scrimmage for 16 ards. He then throws a 46-yard forward pass straight downfield perpendicular to the line of scrimmage. The receiver is tackled immediately. How far is the football displaced from its original position? b. 39 yards

Question 2

3.1 Motion of a Spacecraft in Interstellar Space If the displacement of an object is given in SI units by Δx = −5t + t 2, at t = 2 s its velocity and acceleration are, respectively: (Hint: Use dimensional analysis along with the equations for motion with constant acceleration.) c. negative, positive. Question 3

3.1 Motion of a Spacecraft in Interstellar Space A cheetah can run at approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 60.0 m ahead, how long before the cheetah catches its prey? a. 10.8 s Question 4

3.1 Motion of a Spacecraft in Interstellar Space A baseball batter hits an incoming 40 m/s fastball. The ball leaves the bat at 60 m/s after a ball-on-bat a. 500 N Question 5

A stone is thrown with an initial speed of 10.6 m/s at an angle of 57° above the horizontal from the top of a 32 m building. If g = 9.8 m/s2 and air resistance is negligible, then what is the magnitude of the vertical velocity component of the rock as it hits the ground? e. 27 m/s

SHORT QUIZ 3 Question 1

3.2 Normal Forces and Weight An elevator weighing 20,000 N is supported by a steel cable. What is the tension in the cable when the b. 24,100 N

Question 2

A boat moves through the water in a river at a speed of 8 m/s relative to the water. The boat makes a trip downstream and then makes a return trip upstream to the original starting place. Which trip takes longer? a. the upstream trip Question 3

In a 2-dimensional Cartesian coordinate system the x-component of a given vector is equal to that vector's magnitude multiplied by which trigonometric function, with respect to the angle between vector and x-axis? c. cosine Question 4

In a 2-dimensional Cartesian system, the x-component of a vector is known, and the angle between vector and x-axis is known. Which operation is used to calculate the magnitude of the vector? (taken c. dividing by cosine Question 5

The highest mountain on Mars is Olympus Mons, rising 22 000 meters above the Martian surface. If we were to throw an object horizontally off the mountain top, how long would it take to reach the surface? d. 1.8 minutes Question 6

A plane is moving due north, directly towards its destination. Its airspeed is 220 mph. A constant breeze is blowing from west to east at 20 mph. At what rate is the plane moving north? a. 219 mph Question 7

3.1 Motion of a Spacecraft in Interstellar Space An automobile of mass 2000 kg moving at 20 m/s is braked suddenly with a constant braking force of 10,000 N. How far does the car travel before stopping? a. 40 m Question 8

3.3 Adding Friction to the Mix

A horizontal force of 750 N is needed to overcome the force of static friction between a level floor and a 250-kg crate. What is the acceleration of the crate if the 750-N force is maintained after the crate begins to move and the coefficient of kinetic friction is 0.16? b. 1.4 m/s2 Question 9

A rock is rolled in the sand. It starts at 5.0 m/s, moves in a straight line for a distance of 6.0 m, and then stops. What is the magnitude of the average acceleration? c. 2.1 m/s2 Question 10

3.1 Motion of a Spacecraft in Interstellar Space A vehicle designed to operate on a drag strip accelerates from zero to 30 m/s while undergoing a straight line path displacement of 60 m. What is the vehicle's acceleration if its value may be assumed to c. 7.5 m/s2

WEEK 4 LONG QUIZ 1 Question 1

3.4 Free Fall At the top of a cliff 100 m high, Raoul throws a rock upward with velocity 20.0 m/s. How much later should he drop a second rock from rest so both rocks arrive simultaneously at the bottom of the cliff?

c. 2.48 s Question 2

3.1 Motion of a Spacecraft in Interstellar Space A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 100 km/hr in 9.00 s. What distance will the sports car travel during the 9.00 s acceleration period? (Hint: First convert speed to m/s.) b. 125 m Question 3

Arvin the Ant travels 35 cm eastward, then 25 cm northward, and finally 10 cm westward. What is Arvin's direction of displacement with respect to his original position? a. 45° N of E Question 4

3.4 Free Fall John throws a rock down with speed 20 m/s from the top of a 30-m tower. If g = 9.8 m/s2 and air resistance is negligible, what is the rock's speed just as it hits the ground? c. 31 m/s Question 5

2.4 Newton's Laws of Motion Two forces act on a 6.00-kg object. One of the forces is 11.0 N. If the object accelerates at 2.00 m/s2, what is the greatest possible magnitude of the other force? c. 23.0 N Question 6

2.2 What is Motion? A hiker walks 200 m east and then walks 100 m north. In what direction is her resulting displacement? b. None of the answers is correct. Question 7

3.2 Normal Forces and Weight Three identical 6.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The cubes are lined up from left to right and a force is applied to the left side of the left cube causing all

three cubes to accelerate to the right at 3.0 m/s2. What is the magnitude of the force exerted on the right cube by the middle cube in this case? b. 18 N Question 8

Since 1983 the standard meter has been defined in terms of which of the following? c. the distance light travels in a certain fraction of a second Question 9

A bird, accelerating from rest at a constant rate, experiences a displacement of 30 m in 9 s. What is the average velocity? c. 3.3 m/s Question 10

1.3 Dealing with Numbers The basic function of an automobile's carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assume that 40 cm3 of gasoline is atomized into N spherical droplets. Each droplet has a radius of 2.0 × 10−5 m. Find the total surface area of these N spherical droplets. d. 60,000 cm2 Question 11

Areas always have dimensions ____ while volumes always have dimensions ____. a. L2, L3 Question 12

A ball is rolled horizontally off a table with an initial speed of 0.21 m/s. A stopwatch measures the ball's trajectory time from table to the floor to be 0.3 s. What is the height of the table? (g = 9.8 m/s2 and air resistance is negligible) e. 0.44 m Question 13

Calculate (0.73 + 0.071) (3.3 X 103), keeping only significant figures. a. 2600

Question 14

A taxicab moves five blocks due north, five blocks due east, and another three blocks due north. Assume all blocks are of equal size. How far is the taxi from its starting point? d. 9.4 blocks Question 15

Suppose a particle is moving along a straight line with a speed v for a time t, then stops for a time t, and then resumes moving along the original direction with speed v for time t. What has been the average speed of the particle for the total time period 3t? b. 2v / 3 Question 16

1.3 Dealing with Numbers Two numbers, one with 4 significant figures and the other with 3 significant figures, are combined using the math operations given below. Which operation can give a result with fewer than 3 significant d. subtraction Question 17

Starting from rest, a car accelerates down a straight road with constant acceleration a for a time t, then the direction of the acceleration is reversed, (i.e., it is −a), and the car comes to a stop in an additional time t, the time for the whole trip being 2t. At what time, or times, is the average velocity of the car for the trip equal to its instantaneous velocity during the trip? a. This occurs at 2 times, 0.5 t and 1.5 t. Question 18

A cereal box has the dimensions of 0.18 m × 0.24 m × 0.080 m. If there are 3.28 feet per meter, then what is the volume of the box in cubic feet? c. 0.12 cubic feet Question 19

A ball of relatively low density is thrown upwards. Because of air resistance the acceleration while traveling upwards is −10.8 m/s2. On its trip downward the resistance is in the opposite direction, and the resulting acceleration is −8.8 m/s2. When the ball reaches the level from which it was thrown, how does its speed compare to that with which it was thrown? c. It is less than the original speed upward.

Question 20

3.2 Normal Forces and Weight A 70.0-kg man jumps 1.00 m down onto a concrete walkway. His downward motion stops in 0.04 seconds. If he forgets to bend his knees, what force is transmitted to his leg bones? b. 8000 N Question 21

Five boys are pushing on a snowball, and each is pushing with a force of 10.0 N. However, each boy is pushing in a different direction. They are pushing north, northeast, east, southeast, and south. (Each boy is pushing at an angle of 45.0° relative to his neighbor.) What is the magnitude of the total force on the ball? c. 24.1 N Question 22

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time) b. at Question 23

3.3 Adding Friction to the Mix Doug hits a hockey puck, giving it an initial velocity of 7.0 m/s. If the coefficient of kinetic friction between ice and puck is 0.050, how far will the puck slide before stopping? b. 50 m Question 24

A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at shoulder level) by the catcher. At what point does the magnitude of the vertical component of velocity have its minimum value? (air resistance is negligible) d. at the top of the trajectory Question 25

Jack pulls a sled across a level field by exerting a force of 150 N at an angle of 30° with the ground. What are the parallel and perpendicular components, respectively, of this force with respect to the ground? c. 130 N, 75 N

Question 26

A string attached to an airborne kite is maintained at an angle of 50° with the horizontal. If a total of 140 m of string is reeled in while bringing the kite back to the ground, what is the horizontal displacement of the kite in the process? (Assume the kite string doesn't sag.) e. 90 m Question 27

A physics class in a large lecture hall has 150 students. The total mass of the students is about ____ kg. b. 106 Question 28

There are other ways of expressing uncertainty besides significant figures. For example, suppose a quantity is known to have a value between 20.4 and 20.0, and our best estimate of the value is midrange at 20.2. We could write the number as 20.2 +/− 0.2 and say that the number has a 1% uncertainty. We would also say it has 3 significant figures. If we square a number with 1% uncertainty (i.e., 2 parts in about 200) and 3 significant figures, what results? c. A number with 2% uncertainty and 3 significant figures. Question 29

3.4 Free Fall The acceleration due to gravity on the Moon's surface is one-sixth that on Earth. What total force would be required to accelerate a 30-kg object at 6.0 m/s2 on the Moon? a. 180 N Question 30

A plane is moving due north, directly towards its destination. Its airspeed is 230 mph. A constant breeze is blowing from west to east at 20 mph. In which direction is the plane pointed? e. 5° W of N

LEARNING ACTIVITY 4 Question 1

4.4 Further Applications of Newton's Laws A 2000-kg sailboat experiences an eastward force of 2000 N by the ocean tide and a wind force against its sails with magnitude of 6000 N directed toward the northwest (45° N of W). What is the magnitude of the resultant acceleration? b. 2.4 m/s2 Question 2

The statement by Newton that "for every action there is an opposite but equal reaction" is regarded as which of his laws of motion? a. third Question 3

4.4 Further Applications of Newton's Laws A 12.0-kg mass is placed on a 25.0° incline and friction keeps it from sliding. The coefficient of static friction in this case is 0.580 and the coefficient of sliding friction is 0.520. The mass is given a shove causing it to slide down the incline. Taking down the incline as positive, what is the acceleration of the mass while it is sliding? d. −0.477 m/s2 Question 4

A block of mass 6.00 kg rests on a horizontal surface where the coefficient of kinetic friction between the two is 0.400. A string attached to the block is pulled horizontally, resulting in a 3-m/s2 acceleration by the block. Find the tension in the string. (g = 9.80 m/s2) c. 41.52 N Question 5

A thrown stone hits a window, but doesn't break it. Instead it reverses direction and ends up on the ground below the window. In this case, we know: a. the force of the stone on the glass = the force of the glass on the stone.

SHORT QUIZ 4 Question 1

4.4 Further Applications of Newton's Laws A 12.0-kg mass is placed on a 25.0° incline and friction keeps it from sliding. The coefficient of static friction in this case is 0.580, and the coefficient of sliding friction is 0.520. The mass is given a shove causing it to slide down the incline. What is the frictional force while the mass is sliding? a. 55.4 N Question 2

4.2 Projectile Motion Superguy is flying at treetop level near Paris when he sees the Eiffel Tower elevator start to fall (the cable snapped). His x-ray vision tells him Lois LaTour is inside. If Superguy is 1.00 km away from the tower, and the elevator falls from a height of 2.1 × 102 m, how long does Superguy have to save Lois, and what must be his average speed? b. 6.5 s, 150 m/s Question 3

4.4 Further Applications of Newton's Laws A 150-N sled is pulled up a 28° slope at a constant speed by a force of 120 N. What is the coefficient of kinetic friction between sled and slope? a. 0.37 Question 4

Two objects, A and B, are placed on an inclined plane that can be rotated to different angles of elevation. A starts to slide at twice the angle of elevation that B starts sliding. The respective coefficients for static friction for A and B are μA and μB. Choose the last answer that is correct. d. μA > μB Question 5

A rock is rolled in the sand. It starts at 6.0 m/s, moves in a straight line for a distance of 4.5 m, and then stops. What is the magnitude of the average acceleration? d. 4 m/s2

Question 6

Two blocks of masses 22 kg and 9 kg are connected together by a light string and rest on a frictionless level surface. Attached to the 9-kg mass is another light string, which a person uses to pull both blocks horizontally. If the two-block system accelerates at 0.7 m/s2, what is the tension in the second string attached to the 8-kg mass? c. 21.7 N Question 7

A 411-N crate rests on an ramp; the maximum angle just before it slips is 20° with the horizontal. What is the coefficient of static friction between crate and ramp surfaces? c. 0.36 Question 8

A 500-N tightrope walker stands at the center of the rope. If the rope can withstand a tension of 2,000 N without breaking, what is the minimum angle the rope can make with the horizontal? e. 7° Question 9

4.2 Projectile Motion A baseball leaves the bat with a speed of 44.0 m/s and an angle of 30.0° above the horizontal. A 4.0-m high fence is located at a horizontal distance of 132 m from the point where the ball is struck. Assuming the ball leaves the bat 1.0 m above ground level, by how much does the ball clear the fence? c. 14.4 m Question 10

As I slide a box at constant speed up a frictionless slope, pulling parallel to the slope, the tension in the rope will be: b. less than the weight of the box.

WEEK 6 LEARNING ACTIVITY 5 Question 1

An object of mass 0.50 kg is transported to the surface of Planet X where the object's weight is measured to be 10 N. The radius of the planet is 4.0 × 106 m. What is the mass of Planet X? (G = 6.67 × 10−11 N × m2/kg2) c. 4.8 × 1024 kg Question 2

A 1.00-kg ball has zero potential and kinetic energy. Maria drops the ball into a 10.00-m-deep well. After the ball comes to a stop in the mud, the sum of its potential and kinetic energy is: a. −98 J. Question 3

Adisa pulls a 45-N crate up a 5.0-m long inclined plane at a constant velocity. If the plane is inclined at an angle of 40° to the horizontal and there is a constant force of friction of 14 N between the crate and the surface, what is the net change in potential energy of the crate? b. 145 J Question 4

Which of the following is an example of a nonconservative force? d. friction Question 5

A 70.0-kg (including the passenger) sled is subject to a net force of 30.0 N pushing in the direction of the sled's motion as it is moving over a horizontal surface for a distance of 12.0 m after having started from rest. At this point the sled is released as it starts down a 10.0° incline. However, the snow is not very deep, and the sled stops after having moved an additional 45.0 m. What is the work done by friction while the sled is on the incline? a. -5829.92 J

SHORT QUIZ 5 Question 1

Is it possible for the total mechanical energy of a moving particle to be negative? b. yes Question 2

5.1 Uniform Circular Motion At what speed will a car round a 125 m radius curve, banked at a 45° angle, if no friction is required between the road and tires to prevent the car from slipping? (g = 9.8 m/s2) a. 35 m/s Question 3

An automobile delivers 34.0 hp to its wheels when moving at a constant speed of 21.0 m/s. What is the resistance force on the automobile at this speed? (1 hp = 746 watts) d. 1 210 N Question 4

A 60-kg woman runs up a flight of stairs having a rise of 4.1 m in a time of 4.2 s. What average power did she supply? c. 574 W Question 5

A pole vaulter clears 6.00 m. With what speed does he strike the mat in the landing area? d. 10.8 m/s Question 6

Preston pushes a wheelbarrow weighing 480 N to the top of a 50.0-m ramp, inclined at 25.0° with the horizontal, and leaves it. Tamara accidentally bumps the wheelbarrow. It slides back down the ramp, during which an 75.0-N frictional force acts on it over the 50.0 m. What is the wheelbarrow's kinetic energy at the bottom at of the ramp? (g = 9.8 m/s2) b. 6,393 J

Question 7

A force of 120 N is applied to a 50-kg mass in the direction of motion for a distance of 7.0 m and then the force is increased to 160 N for the next 3.0 m. For the 10 m of travel, how much work is done by the varying force? e. 1 320 J Question 8

If during a given physical process the only force acting on an object is friction, which of the following must be assumed in regard to the object's kinetic energy? c. It cannot be determined from the information given. Question 9

A golf ball hits a wall and bounces back at 2/5 the original speed. What part of the original kinetic energy of the ball did it lose in the collision? e. 21/25 Question 10

A girl and her bicycle have a total mass of 43.0 kg. At the top of the hill her speed is 5.0 m/s, and her speed doubles as she rides down the hill. The hill is 10.0 m high and 105 m long. How much kinetic energy and potential energy is lost to friction? c. 2,602 J

WEEK 7 LEARNING ACTIVITY 6 Question 1

Ann the Astronaut weighs 60 kg. She is space walking outside the space shuttle and pushes a 350-kg satellite away from the shuttle at 0.70 m/s. What speed does this give Ann as she moves toward the shuttle? b. 4.1 m/s Question 2

6.7 Power Yuri, a Russian weightlifter, is able to lift 300 kg a distance 2.00 m in 2.00 s. What is his power output? b. 2.94 kW Question 3

A 5-kg object is moving to the right at 4 m/s and collides with a 4-kg object moving to the left at 5 m/s. The objects collide and stick together. After the collision, the combined object: b. has no kinetic energy. Question 4

A pendulum consists of a mass m suspended from a string of length L. When the pendulum is swinging, how much greater is the mass's potential energy when the string is displaced from the vertical by the angle θ than when the mass is at the lowest position? a. mgL(1 - cosθ) Question 5

6.5 Conservative Versus Nonconservative Forces and Conservation of Energy A baseball catcher puts on an exhibition by catching a 0.150-kg ball dropped from a helicopter at a height of 100 m above the catcher. If the catcher "gives" with the ball for a distance of 0.500 m while catching it, what average force is exerted on the mitt by the ball? (g = 9.80 m/s2) a. 295 N

SHORT QUIZ 6 Question 1

In an automobile collision, how does an airbag lessen the blow to the passenger? Assume as a result of the collision, the passenger stops. a. The stopping impulse is the same for either the hard objects or the airbag. Unlike the windshield or dashboard, the air bag gives some increasing the time for the slowing process and thus decreasing the average force on the passenger. Question 2

The units of impulse are equivalent to: d. kg⋅m/s. Question 3

6.7 Power A 400-hp engine can deliver, in SI units, an average power of _____. (1 hp = 746 W) a. 298,000 W Question 4

In a two-body collision, if the kinetic energy of the system is conserved, then which of the following best describes the momentum after the collision? d. must also be conserved Question 5

6.2 Kinetic Energy and the Work-Energy Theorem What is the kinetic energy of a 0.160-kg ball thrown at 40.0 m/s (90.0 mph)? a. 128 J Question 6

Two particles collide, one of them initially being at rest. Is it possible for both particles to be at rest after the collision? a. No.

Question 7

A billiard ball is moving in the x-direction at 30.0 cm/s and strikes another billiard ball moving in the ydirection at 40.0 cm/s. As a result of the collision, the first ball moves at 50.0 cm/s, and the second ball stops. What is the change in kinetic energy of the system as a result of the collision? c. 0 Question 8

A neutron in a nuclear reactor makes an elastic head-on collision with a carbon atom initially at rest. (The mass of the carbon atom is 12 times that of the neutron.) What fraction of the neutron's kinetic energy is transferred to the carbon atom? a. 28.4% Question 9

6.3 Potential Energy A simple pendulum, 2.0 m in length, is released by a push when the support string is at an angle of 25° from the vertical. If the initial speed of the suspended mass is 3.0 m/s when at the release point, to what maximum angle will it move in the second half of its swing? c. 47° Question 10

6.5 Conservative Versus Nonconservative Forces and Conservation of Energy A girl and her bicycle have a total mass of 40 kg. At the top of the hill her speed is 5.0 m/s. The hill is 10 m high and 100 m long. If the force of friction as she rides down the hill is 24 N, what is her speed at the bottom? b. 10 m/s

WEEK 8 LEARNING ACTIVITY 7 Question 1

Jerome pitches a baseball of mass 0.15 kg. The ball arrives at home plate with a speed of 40 m/s and is batted straight back to Jerome with a return speed of 60 m/s. What is the magnitude of change in the ball's momentum?

b. 15 kg

m/s

Question 2

A 6-kg object is moving to the right at 4 m/s and collides with a 4-kg object moving to the left at 6 m/s. The objects collide and stick together. After the collision, the combined object: b. has no kinetic energy. Question 3

A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s2. What is the time interval required for it to reach a 4.2-rad displacement after starting from rest? d. 18 s Question 4

At liftoff, the engines of the Saturn V rocket consumed 14,000 kg/s of fuel and exhausted the combustion products at 2900 m/s. What was the total upward force (thrust) provided by the engines? a. 4.06 × 107 N Question 5

A satellite is in a circular orbit about the Earth at a distance of one Earth radius above the surface. What is the speed of the satellite? (The radius of the Earth is 6.4 × 106 m, and G = 6.67 × 10−11 N⋅m2/kg2.) d. 5 600 m/s

SHORT QUIZ 7 Question 1

A 1.00-kg duck is flying overhead at 1.50 m/s when a hunter fires straight up. The 0.0100-kg bullet is moving 200 m/s when it hits the duck and stays lodged in the duck's body. What is the speed of the duck and bullet immediately after the hit? d. 2.48 m/s Question 2

Suppose the gravitational potential energy for a mass at an altitude of one Earth radius is PE1 and at two Earth radii is PE2. How do the absolute values of these potential energies compare? d. | PE1 | < 2 | PE2 | Question 3

For any object orbiting the Sun, Kepler's Law may be written T2 = kr3. If T is measured in years and r in units of the Earth's distance from the Sun, then k = 1. What, therefore, is the time (in years) for Mars to orbit the Sun if its mean radius from the Sun is 1.5 times the Earth's distance from the Sun? a. 1.8 years Question 4

An asteroid in orbit about the sun has a linear speed of 4 km/s when at a distance of closest approach d from the sun. What is its linear speed when it is at its greatest distance from the sun, a distance 2 d? b. 2 km/s Question 5

2 600 rev/min is equivalent to which of the following? d. 273 rad/s Question 6

Alex throws a 0.15-kg rubber ball down onto the floor. The ball's speed just before impact is 6.5 m/s and just after is 3.5 m/s. If the ball is in contact with the floor for 0.050 s, what is the magnitude of the average force applied by the floor on the ball? c. 30 N

Question 7

A Ferris wheel, rotating initially at an angular speed of 0.50 rad/s, accelerates over a 7.0-s interval at a rate of 0.040 rad/s2. What is its angular speed after this 7-s interval? a. 0.78 rad/s Question 8

A model car is propelled by a cylinder of carbon dioxide gas. The cylinder emits gas at a rate of 4.5 g/s with an exit speed of 80.0 m/s. The car has a mass of 200 g, including the CO2 cylinder. Starting from rest, what is the car's initial acceleration? b. 1.8 m/s2 Question 9

A 75-kg swimmer dives horizontally off a 250-kg raft initially at rest. If the diver's speed immediately after leaving the raft is 2 m/s, what is the corresponding raft speed? a. 0.6 m/s Question 10

According to Kepler's second law, Halley's Comet circles the Sun in an elliptical path with the Sun at one focus of the ellipse. What is at the other focus of the ellipse? b. nothing

WEEK 9 LONG QUIZ 2 Question 1

4.4 Further Applications of Newton's Laws Jamal pulls a 150-N sled up a 28.0° slope at constant speed by a force of 120 N. Near the top of the hill he releases the sled. With what acceleration does the sled go down the hill? d. 1.36 m/s2

Question 2

6.4 More Potential Energy Functions A Hooke's law spring is compressed 12.0 cm from equilibrium and the potential energy stored is 36.0 J. What is the spring constant in this case? c. 5000 N/m Question 3

An automobile of mass 3,000 kg moving at 45 m/s is braked suddenly with a constant braking force of 9,000 N. How far does the car travel before stopping? e. 338 m Question 4

6.1 Force, Displacement, and Work The net force acting on a 6.0-kg object is given by Fx = (12 - x) N, where Fx is in newtons and x is in meters. How much work is done on the object as it moves from x = 0 to x = 12 m? b. 72 J Question 5

Object 1 has twice the mass of Object 2. Each of the objects has the same magnitude of momentum. Which of the following statements is true? b. One object has twice the kinetic energy of the other. Question 6

6.1 Force, Displacement, and Work A satellite is held in orbit by a 3000-N gravitational force. Each time the satellite completes an orbit of circumference 80,000 km, the work done on it by gravity is: c. 0 Question 7

A 0.15-m-radius grinding wheel starts at rest and develops an angular speed of 12.0 rad/s in 4.0 s. What is the average tangential acceleration of a point on the wheel's edge? c. 0.45 m/s2

Question 8

Rita accelerates a 0.45-kg ball from rest to 8.0 m/s during the 0.15 s in which her foot is in contact with the ball. What average force does she apply to the ball during the kick? b. 24 N Question 9

4.4 Further Applications of Newton's Laws A 15-kg block rests on a level, frictionless surface and is attached by a light string to a 10-kg hanging mass where the string passes over a massless frictionless pulley. If g = 9.8 m/s2, what is the tension in the connecting string? b. 59 N Question 10

A sled weighs 100 N. It is held in place on a frictionless 20° slope by a rope attached to a stake at the top; the rope is parallel to the slope. What is the normal force of the slope acting on the sled? a. 94 N Question 11

Alex throws a 0.10-kg rubber ball down onto the floor. The ball's speed just before impact is 5.5 m/s, and just after is 3.5 m/s. If the ball is in contact with the floor for 0.02 s, what is the magnitude of the average force applied by the floor on the ball? a. 45 N Question 12

6.3 Potential Energy A pole-vaulter clears 5.00 m. With what speed does he strike the mat in the landing area? a. 9.90 m/s Question 13

A 100-kg crate is placed on an adjustable inclined plane. As one end of the incline is raised, the crate begins to move downward. If the crate slides down the plane with an acceleration of 0.60 m/s2 when the incline angle is 25°, what is the coefficient of kinetic friction between ramp and crate? (g = 9.8 m/s2) a. 0.4

Question 14

A billiard ball collides in an elastic head-on collision with a second stationary identical ball. After the collision which of the following conditions applies to the first ball? d. comes to rest Question 15

6.3 Potential Energy A 10.0-kg box starts at rest and slides 6.0 m down a ramp inclined at an angle of 10° with the horizontal. If there is no friction between the ramp surface and crate, what is the velocity of the crate at the bottom of the ramp? (g = 9.8 m/s2) b. 4.5 m/s Question 16

6.7 Power Four different compact fluorescent bulbs and their comparison to incandescent bulbs are advertised as follows: a 42-W cfl produces the light of a 150-W incandescent, a 9-W cfl produces the light of a 40-W incandescent, a 23-W cfl produces the light of a 100-W incandescent,and a 13-W cfl produces the light of a 60-W incandescent. Which cfl produces the most light per watt, and which one produces the least? Assume true advertising! c. the 13 W, the 42 W Question 17

6.5 Conservative Versus Nonconservative Forces and Conservation of Energy A worker pushes a sled with a force of 40 N over a level distance of 6.0 m. If a frictional force of 16 N acts on the wheelbarrow in a direction opposite to that of the worker, what total work is done on the wheelbarrow? d. 144 J Question 18

4.3 A First Look at Reference Frames and Relative Velocity A boat travels upstream and after one hour has gone 10 km. The boat next travels downstream and after one hour has gone 16 km. If the boat's speed relative to the water is constant, what is the speed of the current in the river? d. 3 km/h

Question 19

6.3 Potential Energy An 80,000-kg airliner is flying at 900 km/h at a height of 8.00 km. What is its total energy (kinetic + potential) if the total was 0 when the airliner was at rest on the ground? a. 8770 MJ Question 20

You are facing east looking at the clock on the wall. You see the second hand moving clockwise (of course). In what direction is the angular velocity vector for this second hand? c. east Question 21

4.2 Projectile Motion A ball is rolled horizontally off a table with an initial speed of 0.18 m/s. A stopwatch measures the ball's trajectory time from table to the floor to be 0.30 s. How far away from the table does the ball land? Note: g = 9.8 m/s2 and air resistance is negligible. a. 0.054 m Question 22

A 500-N tightrope walker stands at the center of the rope such that each half of the rope makes an angle of 15.0° with the horizontal. What is the tension in the rope? b. 970 N Question 24

A 7.0-kg bowling ball strikes a 2.5-kg pin. The pin flies forward with a velocity of 3.5 m/s; the ball continues forward at 6.0 m/s. What was the original velocity of the ball? e. 5.6 m/s Question 25

4.2 Projectile Motion A helicopter is traveling at 54 m/s at a constant altitude of 100 m over a level field. If a wheel falls off the helicopter, with what speed will it hit the ground? Note: g = 9.8 m/s2 and air resistance is negligible. d. 70 m/s

Question 26

An Olympic skier moving at 15.0 m/s down a 30.0° slope encounters a region of wet snow, of coefficient of friction μk = 0.740. How far down the slope does she go before stopping? a. 81 m Question 27

Consider a point on a bicycle wheel as the wheel turns about a fixed axis, neither speeding up nor slowing down. Compare the linear and angular accelerations of the point. d. Only the angular acceleration is zero. Question 28

A ventilation fan has blades 0.25 m in radius rotating at 20 rpm. What is the tangential speed of each blade tip? a. 0.52 m/s Question 29

A box slides up an incline with an angle of elevation θ. When the box reaches its maximum distance up the incline it stops and does not slide down the incline due to friction. What is the minimum value of the coefficient of static friction for this to occur? b. μs = tanθ Question 30

At an altitude of 4 times the radius of the earth, the acceleration due to gravity is c. not given.

WEEK 10 FIRST QUARTER EXAM Question 1

A box is launched up a frictionless incline with an angle of elevation θ. The maximum height reached by the box is h. The box is again launched up the incline with the same initial speed it had before, but this time the angle of elevation has been increased to φ. How does the maximum height H reached this time by the box compare with the previous value h? b. H = h Question 2

Three identical 5.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The cubes are lined up from left to right and a force is applied to the left side of the left cube causing all three cubes to accelerate to the right at 4.0 m/s2. What is the magnitude of the force exerted on the middle cube by the left cube in this case? a. 40 N Question 3

A car is moving in the positive direction along a straight highway and accelerates at a constant rate while going from point A to point B. If the acceleration is positive, increasing the speed of the car, when does the position where the average speed equals the instantaneous speed occur during the time interval from A to B? Assume the time interval is T. c. T/2 from the start of the interval Question 4

Kaitlin uses a bat to hit a thrown baseball. She knocks the ball back in the direction from which it came in a partially inelastic collision. The bat, which is heavier than the baseball, continues to move in the same direction after the hit as Kaitlin "follows through." Is the ball moving faster before or after it was hit? d. There is insufficient information to answer this problem.

Question 5

A 13-kg mass and a 3-kg mass are connected by a light string over a massless, frictionless pulley. If g = 9.8 m/s2, what is the acceleration of the system when released? d. 6.1 m/s2 Question 6

3.4 Free Fall Gwen releases a rock at rest from the top of a 50-m tower. If g = 9.8 m/s2 and air resistance is negligible, what is the speed of the rock as it hits the ground? c. 31 m/s Question 7

4.3 A First Look at Reference Frames and Relative Velocity A plane is moving due north, directly towards its destination. Its airspeed is 200 mph. A constant breeze is blowing from west to east at 40 mph. How long will it take for the plane to travel 200 miles north? b. more than one hour Question 8

A billiard ball collides in an elastic head-on collision with a second identical ball. What is the kinetic energy of the system after the collision compared to that before collision? b. the same as Question 9

4.2 Projectile Motion A baseball thrown from the outfield is released from shoulder height at an initial velocity of 39.2 m/s at an initial angle of 30.0° with respect to the horizontal. What is the maximum vertical displacement that the ball reaches during its trajectory? a. 19.6 m Question 10

A projectile is fired directly upwards at 49.6 m/s. A second projectile is dropped from rest at some higher elevation at the instant the first projectile is fired and passes the first projectile 3.63 s later. From the frame of reference of the first projectile, what is the velocity of the second projectile as it passes by? b. 49.6 m/s, downward

Question 11

3.6 Reasoning and Relationships: Finding the Missing Piece Assume everyone in the United States consumes one soft drink in an aluminum can every two days. If there are 300 million Americans, how many tons of aluminum need to be recycled each year if each can weighs 1/16 pound, and one ton = 2000 pounds? c. 1.7 million tons Question 12

4.1 Statics A 200-N block, on a 30° incline, is being held motionless by friction. The coefficient of static friction between the block and the plane is 0.60. The force due to friction is: a. 100 N. Question 13

In a partially elastic collision between two objects with unequal mass: c. the momentum of one will increase by the amount that the momentum of the other decreases. Question 14

4.1 Statics A 4000-N weight is suspended in equilibrium by two cables. Cable 1 applies a horizontal force to the right of the object and has a tension T1. Cable 2 applies a force upward and to the left at an angle of 37.0° to the negative x axis and has a tension T2. Find T2. c. 6650 N Question 15

Four vectors all have the same magnitude. Vector 1 is at 30°, Vector 2 is at 110°, vector 3 is at 240°, and Vector 4 is at 315°. Which vector has the greatest magnitude x component and which vector has the least magnitude y component? c. Vector 1, Vector 1 Question 16

3.4 Free Fall Omar throws a rock down with speed 2.0 m/s from the top of a tower. The rock hits the ground after 2.0 s. What is the height of the tower? (air resistance is negligible) d. 24 m

Question 17

A stone is thrown at an angle of 45° above the horizontal from the top edge of a cliff with an initial speed of 13.6 m/s. A stop watch measures the stone's trajectory time from top of cliff to bottom to be 5.2 s. How far out from the cliff's edge does the stone travel horizontally? (g = 9.8 m/s2 and air resistance is negligible) e. 50 m Question 18

A right triangle has sides 5.0 m, 12 m, and 13 m. The largest angle not 90° of this triangle is nearest: c. 67°. Question 19

Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 8 and 9 cm, how many significant figures will result if you only use the part of the meter stick between the 82- and 93-cm positions? a. 3 Question 20

A 4.0 ft by 8.0 ft sheet of plywood of uniform density and thickness lies in the 1st quadrant with its long side along the x axis, one corner at the origin, and the diagonally opposite corner at position (x, y) = (8.0 ft, 4.0 ft). The lower right 2.0 ft by 4.0 ft quarter of the sheet is removed from the sheet. What are the coordinates of the center of mass of the remaining portion of the sheet? d. (3.3 ft, 2.3 ft) Question 21

4.1 Statics A trapeze artist, with swing, weighs 700 N; he is being held to one side by his partner so that the swing ropes make an angle of 30.0° with the vertical. In such a condition of static equilibrium what is the tension in the rope? b. 808 N Question 22

In which of the following cases is the displacement's magnitude half the distance traveled? a. 9 steps east followed by 3 steps west

Question 23

A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s2. What is its angular speed at the instant it goes through an angular displacement of 4.2 rad? c. 0.46 rad/s Question 24

3.2 Normal Forces and Weight The acceleration due to gravity on the Moon's surface is one-sixth that on Earth. An astronaut's life support backpack weighs 240 lb on Earth. What does it weigh on the Moon? c. 40 lb Question 25

In 1983 the standard meter was redefined to what it is currently. What was the previous definition from 1960 based on? b. wavelength of light emitted by certain krypton atoms Question 26

Doubling the mean distance from the Sun results in changing the orbital period of revolution by what factor? b. 23/2 Question 27

Vector A is 2 m long, and vector B is 5 m long. The length of the sum of the vectors must be a. some value from 3 m to 7 m. Question 28

3.1 Motion of a Spacecraft in Interstellar Space A cheetah can maintain its maximum speed of 100 km/hr for 35.0 seconds. What minimum distance must a gazelle running 80.0 km/hr be ahead of the cheetah to escape? d. 194 m Question 29

A 20-g bullet moving at 1000 m/s is fired through a one-kg block of wood emerging at a speed of 200 m/s. What is the kinetic energy of the block that results from the collision if the block had not been moving prior to the collision and was free to move?

b. 0.13 kJ Question 30

I walk six miles in a straight line in a direction north of east, and I end up four miles north and several miles east. How many degrees north of east have I walked? c. 42° Question 31

A 0.10-kg ball is moving at 5 m/s when it is hit by a bat, causing it to reverse direction and have a speed of 12 m/s. What is the change in the magnitude of the momentum of the ball? c. 1.7 kg⋅m/s Question 32

The basic function of an automobile's carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assume that 25cm3 of gasoline is atomized into N spherical droplets. Each droplet has a radius of 1.0 × 10−5 m. Find the total surface area of these N spherical droplets. e. 75,000 cm2 Question 33

A 20-kg object sitting at rest is struck elastically in a head-on collision with a 12-kg object initially moving at +4.0 m/s. Find the final velocity of the 20-kg object after the collision. a. +3.0 m/s Question 34

If we know an object is moving at constant velocity, we may assume: a. the net force acting on the object is zero. Question 35

Plane A is flying at 430 mph in the northeast direction relative to the earth. Plane B is flying at 500 mph in the north direction relative to the earth. What is the speed of Plane B as observed from Plane A? e. 362 mph Question 36

A helicopter stays aloft by pushing large quantities of air downward every second. What mass of air must be pushed downward at 30.0 m/s every second to keep a 1000 kg helicopter aloft?

d. 327 kg Question 37

Neglecting gravity, doubling the exhaust velocity from a single stage rocket initially at rest changes the final kinetic energy of the burnout stage by what factor? Assume all other variables, such as the mass of the rocket and the mass of the fuel, do not change. d. It quadruples. Question 38

3.3 Adding Friction to the Mix Hector drives a pickup truck horizontally at 15.0 m/s. He is transporting a crate of delicate lead crystal. If the coefficient of static friction between the crate and the truck bed is 0.300, what is the minimum stopping distance for the truck so the crate will not slide? c. 38.3 m Question 39

6.5 Conservative Versus Nonconservative Forces and Conservation of Energy A girl and her bicycle have a total mass of 40.0 kg. At the top of the hill her speed is 5.0 m/s, and her speed doubles as she rides down the hill. The hill is 12.0 m high and 100 m long. How much kinetic energy and potential energy is lost to friction? c. 3200 J Question 40

At what speed will a car round a 52-m-radius curve, banked at a 45° angle, if no friction is required between the road and tires to prevent the car from slipping? (g = 9.8 m/s2) c. 23 m/s Question 41

1.3 Dealing with Numbers tripling the radius of a sphere results in increasing its volume by a factor of c. 27 Question 42

Consider the cosine of any angle between 35° and 40°. If the angle were doubled, what would happen to the cosine of the angle.

c. It would decrease to less than half its original value. Question 43

Which of the following best describes the property of the period of orbital revolution for an Earth satellite? d. greater when the orbital radius is larger Question 44

A roller coaster, loaded with passengers, has a mass of 2 000 kg; the radius of curvature of the track at the bottom point of the dip is 24 m. If the vehicle has a speed of 18 m/s at this point, what force is exerted on the vehicle by the track? (g = 9.8 m/s2) a. 4.7 × 104 N Question 45

A 5-kg object is moving to the right at 4 m/s and collides with another object moving to the left at 5 m/s. The objects collide and stick together. After the collision, the combined object: d. has less kinetic energy than the system had before the collision. Question 46

A bird, accelerating from rest at a constant rate, experiences a displacement of 35 m in 10 s. What is its acceleration? e. 0.70 m/s2 Question 47

2.2 What is Motion? Which of the following is not a vector quantity? c. temperature Question 48

Vector 1 is 7 units long and is at 45°. Vector 2 is 5 units long and is at 150°. Vector 3 is 3 units long and is at 80°. Which vector has equal magnitude components? a. Vector 1 Question 49

Multiplying a 2 significant figure number by a 4 significant figure number and then dividing the product by a seven significant figure number yields a number with how many significant figures?

c. 2 Question 50

6.3 Potential Energy A baseball outfielder throws a baseball of mass 0.15 kg at a speed of 30 m/s and initial angle of 30°. What is the kinetic energy of the baseball at the highest point of the trajectory? Ignore air friction. b. 51 J

PHYC 121 WEEK 1 – 10 LEARNING ACTIVITY 2 – 7 SHORT QUIZ 1 – 7 LONG QUIZ 1 – 2 FIRST QUARTER EXAM