Deck 3: Vectors and Two-Dimensional Motion: Part A

Question 1

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) 6.30 s
B) 21.6 s
C) 5.40 s
D) 10.8 s

Answer 1

10.8 s

Question 2

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?

A) 194 m
B) 167 m
C) 70.0 m
D) 125 m

Answer 2

194 m

Question 3

Rita accelerates a 0.40-kg ball from rest to 12 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?

A) 48 N
B) 32 N
C) 24 N
D) 64 N

Answer 3

32 N

Question 4

When a drag strip vehicle reaches a velocity of 60 m/s,it begins a negative acceleration by releasing a drag chute and applying its brakes.While reducing its velocity back to zero,its acceleration along a straight line path is a constant −6.0 m/s².What displacement does it undergo during this deceleration period?

A) 120 m
B) 300 m
C) 320 m
D) 240 m

Question 5

A drag racer starts from rest and accelerates at 8.0 m/s² for the entire distance of 400 m (1/4 mile).What is the speed of the race car at the end of the run?

A) 32 m/s
B) 40 m/s
C) 64 m/s
D) 80 m/s

Question 6

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?

A) 2.1 m/s²
B) 4.2 m/s²
C) 5.4 m/s²
D) 6.2 m/s²

Question 7

A speeding car traveling at a constant velocity of 24 m/s passes a police care initially at rest beside the roadway.If the police car with constant acceleration of 3.0 m/s² immediately pursues the speeding car,how far down the road does it draw even with the speeding car?

A) 190 m
B) 290 m
C) 380 m
D) 770 m

Question 8

A barefoot field-goal kicker imparts a speed of 30 m/s to a football at rest.If the football has a mass of 0.50 kg and time of contact with the football is 0.020 s,what is the force exerted on the foot?

A) 190 N
B) 380 N
C) 600 N
D) 750 N

Question 9

A cart is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 4.0 m/s².What is the magnitude of the cart's displacement during the first 6.0 s of its motion?

A) 10 m
B) 55 m
C) 66 m
D) 102 m

Question 10

A Cessna aircraft has a liftoff speed of 120 km/hr.What minimum constant acceleration does this require if the aircraft is to be airborne after a takeoff run of 200 m?

A) 2.31 m/s²
B) 2.78 m/s²
C) 4.63 m/s²
D) 5.55 m/s²

Question 11

A shot-putter moves his arm and the 7.0-kg shot through a distance of 1.0 m,giving the shot a velocity of 15 m/s from rest.Find the average force exerted on the shot during this time.

A) 197 N
B) 394 N
C) 600 N
D) 790 N

Question 12

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
B) 80 m
C) 120 m
D) 160 m

Question 13

A speeding car traveling at a constant velocity of v passes a police car initially at rest beside the roadway.If the police car with constant acceleration of a immediately pursues the speeding car,how long is it before the police car is directly behind the speeding car?

A) v/a
B) 2v/a
C) v/2a
D) v​²/a

Question 14

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. )

A) positive,positive.
B) positive,negative.
C) negative,negative.
D) negative,positive.

Question 15

Norma releases a bowling ball from rest;it rolls down a ramp with constant acceleration.After half a second it has traveled 0.40 m.How far has it traveled after two seconds?

A) 3.2 m
B) 6.4 m
C) 9.0 m
D) 16 m

Question 16

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 be constant?

A) 2.0 m/s²
B) 7.5 m/s²
C) 10 m/s²
D) 15 m/s²

Question 17

A karate master strikes a board with an initial velocity of 10.0 m/s,decreasing to 2.0 m/s as his hand passes through the board.If the time of contact with the board is 0.0020 s,and the mass of the coordinated hand and arm is 1.0 kg,what is the force exerted on the board?

A) 1000 N
B) 6000 N
C) 4000 N
D) 4500 N

Question 18

A baseball batter hits an incoming 40 m/s fastball.The ball leaves the bat at 60 m/s after a ball-on-bat contact time of 0.030 s.What is the force exerted on the 0.15 kg baseball?

A) 450 N
B) 250 N
C) 90 N
D) 500 N

Question 19

An automobile driver puts on the brakes and decelerates from 30.0 m/s to zero in 12.0 s.What distance does the car travel?

A) 150 m
B) 180 m
C) 360 m
D) 750 m

Question 20

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. )

A) 55.5 m
B) 125 m
C) 111 m
D) 250 m

Question 21

Three identical 3.0-kg cubes are placed on a horizontal surface in contact with one another.The cubes are lined up from left to right and an 18-N force is applied to the left side of the left cube causing all three cubes to accelerate to the right.If the cubes are each subject to a frictional force of 3.0 N,what is the magnitude of the force exerted on the middle cube by the left cube in this case?

A) 18 N
B) 6 N
C) 12 N
D) none of the above

Question 22

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?

A) 28.7 m
B) 51.0 m
C) 38.3 m
D) 44.4 m

Question 23

There are six books in a stack,each with a weight of 3.0 N.The coefficient of friction between all the books is 0.20 as is the coefficient between the table and the bottom book.What horizontal push must I just exceed on the next to bottom book to start sliding the top five books off the bottom one?

A) 1.0 N
B) 5.0 N
C) 3.0 N
D) 7.0 N

Question 24

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?

A) 700 N
B) 4000 N
C) 8000 N
D) 16,000 N

Question 25

A baseball is released at rest from the top of the Washington Monument.It hits the ground after falling for 5.0 s.What was the height from which the ball was dropped? (g = 9.8 m/s² and assume air resistance is negligible)

A) 1.5 × 10² m
B) 1.8 × 10² m
C) 1.2 × 10² m
D) 2.1 × 10² m

Question 26

The coefficient of friction between a racecar's wheels and the track is 1.0.The car starts from rest and accelerates at a constant rate for 300 m.Find the maximum speed at the end of the race.

A) 44 m/s
B) 77 m/s
C) 89 m/s
D) 99 m/s

Question 27

A hockey puck moving at 8.0 m/s coasts to a halt in 75 m on a smooth ice surface.What is the coefficient of friction between the ice and the puck?

A) µ = 0.025
B) µ = 0.033
C) µ = 0.12
D) µ = 0.044

Question 28

As a 3.0-kg bucket is being lowered into a 10-m deep well,starting from the top,the tension in the rope is 19.6 N.The acceleration of the bucket will be:

A) 6.5 m/s² downward.
B) 9.8 m/s² upward.
C) zero.
D) 3.3 m/s² downward.

Question 29

A rock is thrown straight down with an initial velocity of 17.5 m/s from a cliff.What is the rock's displacement after 2.0 s? (Acceleration due to gravity is 9.80 m/s². )

A) 28 m
B) 49 m
C) 55 m
D) 64 m

Question 30

A block of mass 5.00 kg rests on a horizontal surface where the coefficient of kinetic friction between the two is 0.200.A string attached to the block is pulled horizontally,resulting in a 3.00 m/s² acceleration by the block.Find the tension in the string.(g = 9.80 m/s²)

A) 0.200 N
B) 9.80 N
C) 19.8 N
D) 24.8 N

Question 31

An elevator weighing 20,000 N is supported by a steel cable.What is the tension in the cable when the elevator is being accelerated upward at a rate of 2.00 m/s²? (g = 9.80 m/s²)

A) 13,900 N
B) 23,100 N
C) 24,100 N
D) 26,100 N

Question 32

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?

A) 19 m
B) 25 m
C) 37 m
D) 50 m

Question 33

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?

A) 40 lb
B) 120 lb
C) 80 lb
D) 240 lb

Question 34

A rock is thrown straight up with an initial velocity of 30.0 m/s.What maximum height will the rock reach before starting to fall downward? (Acceleration due to gravity is 9.80 m/s². )

A) 9.80 m
B) 19.6 m
C) 20.4 m
D) 45.9 m

Question 35

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 middle cube by the left cube in this case?

A) 18 N
B) 27 N
C) 54 N
D) none of the above

Question 36

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?

A) 12 N
B) 18 N
C) 24 N
D) none of the above

Question 37

A rock is thrown straight up with an initial velocity of 24.5 m/s.What time interval elapses between the rock's being thrown and its return to the original launch point? (Acceleration due to gravity is 9.80 m/s². )

A) 4.00 s
B) 5.00 s
C) 8.00 s
D) 10.0 s

Question 38

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?

A) 1.8 m/s²
B) 1.4 m/s²
C) 3.0 m/s²
D) 2.1 m/s²

Question 39

Three identical 3.0-kg cubes are placed on a horizontal surface in contact with one another.The cubes are lined up from left to right and an 18-N force is applied to the left side of the left cube causing all three cubes to accelerate to the right.If the cubes are each subject to a frictional force of 3.0 N,what is the magnitude of the force exerted on the right cube by the middle cube in this case?

A) 18 N
B) 6 N
C) 12 N
D) none of the above

Question 40

A horizontal force of 1000 N is needed to overcome the force of static friction between a level floor and a 250-kg crate.If g = 9.8 m/s²,what is the coefficient of static friction?

A) 4.0
B) 0.51
C) 0.41
D) 0.31

Question 41

A physics class in a large lecture hall has 15 students.The total mass of the students is about _____ kg.(You will need to make a reasonable estimate of a missing physical quantity. )

A) 10²
B) 10³
C) 10⁴
D) 10⁵

Question 42

A string is attached to the ceiling.At the bottom of the string a rope of the same length as the string is attached.In the rope-string system,which of the following is the position of greatest tension? Assume the rope has more mass per unit length than the string.

A) at the bottom of the rope
B) at the top of the rope where it is attached to the string
C) at the bottom of the string where it is attached to the rope
D) at the top of the string

Question 43

A water rocket,launched from the ground,rises vertically with acceleration of 20 m/s² for 1.0 s when it runs out of "fuel." Disregarding air resistance,how high will the rocket rise?

A) 15 m
B) 30 m
C) 61 m
D) 102 m

Question 44

A parachutist jumps out of an airplane and accelerates with gravity to a maximum velocity of 58.8 m/s in 6.00 seconds.She then pulls the parachute cord and after a 4.00-second constant deceleration,descends at 10.0 m/s for 80.0 seconds,reaching the ground.From what height did the parachutist jump?

A) 914 m
B) 1110 m
C) 1520 m
D) 1750 m

Question 45

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?

A) 28 m/s
B) 31 m/s
C) 56 m/s
D) 784 m/s

Question 46

A room has 110 ft² of floor space.What is the approximate volume of the room? (You will need to make a reasonable estimate of a missing physical quantity. )

A) 10³ ft³
B) 10⁴ ft³
C) 10⁵ ft³
D) 10⁶ ft³

Question 47

A stone is thrown downward from a cliff.Take "up" to be the positive direction.Which of the following statements is true about the stone?

A) The velocity is negative,the acceleration is negative,and the speed is negative.
B) The velocity is positive,the acceleration is negative,and the speed is positive.
C) The velocity is negative,the acceleration is negative,and the speed is positive.
D) The velocity is positive,the acceleration is positive,and the speed is positive.

Question 48

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?

A) 750,000 tons
B) 1.5 million tons
C) 1.7 million tons
D) 3 million tons

Question 49

A man of weight W​_man is standing on the second floor and is pulling on a rope to lift a box of weight W​_box from the floor below.The rope,which is of negligible weight,has tension T in it,but the pull of the rope is insufficient to lift the box off the floor.What is the magnitude of the normal force that the second floor exerts on the man in this situation?

A) W​_man
B) W​_man + T
C) W​_man + T + a nonzero portion of W​_box
D) W​_man + T + W​_box

Question 50

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) 30 N
B) 10 N
C) 180 N
D) 49 N

Question 51

A ball is thrown vertically upwards at 29.4 m/s.For its complete trip (up and back down to the starting position),its average speed is:

A) 14.7 m/s.
B) 9.80 m/s.
C) 4.90 m/s.
D) not given.

Question 52

Find the tension in an elevator cable if the 1000-kg elevator is ascending with an acceleration of 1.2 m/s²,upward.

A) 11,000 N
B) 9800 N
C) 8600 N
D) 1200 N

Question 53

A cart of weight 60 N is accelerated across a level surface at 0.15 m/s².What net force acts on the cart? (g = 9.8 m/s²)

A) 0.92 N
B) 0.31 N
C) 3.0 N
D) 4.5 N

Question 54

A rock,released at rest from the top of a tower,hits the ground after 2.0 s.What is the speed of the rock as it hits the ground? (g = 9.8 m/s² and air resistance is negligible)

A) 15 m/s
B) 20 m/s
C) 31 m/s
D) 39 m/s

Question 55

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?

A) 5.05 s
B) 3.76 s
C) 2.48 s
D) 1.78 s

Question 56

Two blocks,joined by a string,have masses of 6.0 and 9.0 kg.They rest on a frictionless,horizontal surface.A second string,attached only to the 6.0-kg block,has horizontal force = 45 N applied to it.Both blocks accelerate.Find the tension in the string between the blocks.

A) 18 N
B) 27 N
C) 12 N
D) 9.0 N

Question 57

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?

A) 12 m/s
B) 28 m/s
C) 31 m/s
D) 78 m/s

Question 58

Two blocks of masses 20 kg and 8.0 kg are connected together by a light string and rest on a frictionless,level surface.Attached to the 20-kg mass is another light string,which a person uses to pull both blocks horizontally.If the two-block system accelerates at 0.50 m/s² what is the tension in the connecting string between the blocks?

A) 14 N
B) 6.0 N
C) 10 N
D) 4.0 N

Question 59

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)

A) 20 m
B) 24 m
C) 44 m
D) 63 m

Question 60

Two blocks of masses 20 kg and 8.0 kg are connected together by a light string and rest on a frictionless,level surface.Attached to the 8.0-kg mass is a second light string,which a person uses to pull both blocks horizontally.If the two-block system accelerates at 1.0 m/s²,what is the tension in the second string attached to the 8.0-kg mass?

A) 14 N
B) 6.0 N
C) 28 N
D) 4.0 N

Question 61

If the drag force on a car is F at a moderate highway speed v,at what speed would the drag force be doubled?

A) 1.2v
B) 1.4v
C) 1.7v
D) 2.0v

Question 62

A steel sphere of mass M has a large spherical cavity inside.A second solid steel sphere has mass 4M,but has the same outer radius as the first sphere.If the terminal velocity of the first sphere is v,what would be the terminal velocity of the second sphere?

A) It would also be v since the geometry is the same and the density of steel is the same.
B) It would be v.
C) It would be 2v.
D) It would be 4v.

Question 63

A cue ball of weight W is falling with acceleration g/2 downward and speed v.What would be the terminal velocity of this ball as it continues to fall?

A) v /2
B) v
C) v
D) 2v

Question 64

A cue ball of weight W is falling with an acceleration downward of g/3 and speed v.What is the magnitude of the drag force on the ball at this moment?

A) 0.33W
B) 0.67W
C) 0.11W
D) There is insufficient information to solve this problem.