Question 1

A 0.28-kg stone you throw rises 34.3 m in the air.The magnitude of the impulse the stone received from your hand while being thrown is

Accepted Answer

A) 0.27 N   s. 
B) 2.7 N   s. 
C) 7.3 N   s. 
D) 9.6 N   s. 
E) 34.3 N   s. 
A) 0.27 N   s. 
B) 2.7 N   s. 
C) 7.3 N   s. 
D) 9.6 N   s. 
E) 34.3 N   s.

Question 2

A 2.0-kg object moving 5.0 m/s collides with and sticks to an 8.0-kg object initially at rest.Determine the kinetic energy lost by the system as a result of this collision.

Accepted Answer

A) 20 J 
B) 15 J 
C) 30 J 
D) 25 J 
E) 5.0 J 
A) 20 J 
B) 15 J 
C) 30 J 
D) 25 J 
E) 5.0 J

Question 3

If you know the impulse that has acted on a body of mass m you can calculate

Accepted Answer

A) its initial velocity. 
B) its final velocity. 
C) its final momentum. 
D) the change in its velocity. 
E) its acceleration during the impulse. 
A) its initial velocity. 
B) its final velocity. 
C) its final momentum. 
D) the change in its velocity. 
E) its acceleration during the impulse.

Question 4

The only force acting on a 2.0-kg object moving along the x axis is shown.If the velocity vx is −2.0 m/s at t = 0,what is the velocity at t = 4.0 s?

Accepted Answer

A) −2.0 m/s 
B) −4.0 m/s 
C) −3.0 m/s 
D) +1.0 m/s 
E) +5.0 m/s 
A) −2.0 m/s 
B) −4.0 m/s 
C) −3.0 m/s 
D) +1.0 m/s 
E) +5.0 m/s

Question 5

Two boys in a canoe toss a baseball back and forth.What effect will this have on the canoe? Neglect (velocity-dependent)frictional forces with water or air.

Accepted Answer

A) None,because the ball remains in the canoe. 
B) The canoe will drift in the direction of the boy who throws the ball harder each time. 
C) The canoe will drift in the direction of the boy who throws the ball with less force each time. 
D) The canoe will oscillate back and forth always moving opposite to the ball. 
E) The canoe will oscillate in the direction of the ball because the canoe and ball exert forces in opposite directions upon the person throwing the ball. 
A) None,because the ball remains in the canoe. 
B) The canoe will drift in the direction of the boy who throws the ball harder each time. 
C) The canoe will drift in the direction of the boy who throws the ball with less force each time. 
D) The canoe will oscillate back and forth always moving opposite to the ball. 
E) The canoe will oscillate in the direction of the ball because the canoe and ball exert forces in opposite directions upon the person throwing the ball.

Question 6

A 10-g bullet moving horizontally with a speed of 2.0 km/s strikes and passes through a 4.0-kg block moving with a speed of 4.2 m/s in the opposite direction on a horizontal frictionless surface.If the block is brought to rest by the collision,what is the kinetic energy of the bullet as it emerges from the block?

Accepted Answer

A) 0.51 kJ 
B) 0.29 kJ 
C) 0.80 kJ 
D) 0.13 kJ 
E) 20 kJ 
A) 0.51 kJ 
B) 0.29 kJ 
C) 0.80 kJ 
D) 0.13 kJ 
E) 20 kJ

Question 7

Exhibit 9-1
Two birds of prey hurtling after the same mouse collide in mid-air and grab each other with their talons.Each 250-g bird is flying at 30 m/s at a 60° angle to the ground.   Use this exhibit to answer the following question(s).
-Refer to Exhibit 9-1.What is the horizontal component of their momentum,in  
,immediately after the collision?

Accepted Answer

A) 0 
B) 6.1 
C) 7.5 
D) 13 
E) 15 
A) 0 
B) 6.1 
C) 7.5 
D) 13 
E) 15

Question 8

Car A rear ends Car B,which has twice the mass of A,on an icy road at a speed low enough so that the collision is essentially elastic.Car B is stopped at a light when it is struck.Car A has mass m and speed v before the collision.After the collision

Accepted Answer

A) each car has half the momentum. 
B) car A stops and car B has momentum mv. 
C) car A stops and car B has momentum 2mv. 
D) the momentum of car B is four times as great in magnitude as that of car A. 
E) each car has half of the kinetic energy. 
A) each car has half the momentum. 
B) car A stops and car B has momentum mv. 
C) car A stops and car B has momentum 2mv. 
D) the momentum of car B is four times as great in magnitude as that of car A. 
E) each car has half of the kinetic energy.

Question 9

A 6.0-kg object moving 2.0 m/s in the positive x direction has a one-dimensional elastic collision with a 4.0-kg object moving 3.0 m/s in the opposite direction.What is the total kinetic energy of the two-mass system after the collision?

Accepted Answer

A) 30 J 
B) 62 J 
C) 20 J 
D) 44 J 
E) 24 J 
A) 30 J 
B) 62 J 
C) 20 J 
D) 44 J 
E) 24 J

Question 10

A 2.0-kg object moving with a velocity of 5.0 m/s in the positive x direction strikes and sticks to a 3.0-kg object moving with a speed of 2.0 m/s in the same direction.How much kinetic energy is lost in this collision?

Accepted Answer

A) 2.4 J 
B) 9.6 J 
C) 5.4 J 
D) 0.6 J 
E) 6.0 J 
A) 2.4 J 
B) 9.6 J 
C) 5.4 J 
D) 0.6 J 
E) 6.0 J

Question 11

Two cars start at the same point,but travel in opposite directions on a circular path of radius R,each at speed v.While each car travels a distance less than  
,one quarter circle,the center of mass of the two cars

Accepted Answer

A) remains at the initial point. 
B) travels along a diameter of the circle at speed v'  v. 
E) remains at the center of the circle. 
A) remains at the initial point. 
B) travels along a diameter of the circle at speed v'  v. 
E) remains at the center of the circle.

Question 12

A catapult fires an 800-kg rock with an initial velocity of 100 m/s at a 40° angle to the ground.The magnitude of the vertical impulse the catapult receives from the rock is

Accepted Answer

A) 5.1 × 104 N   s. 
B) 6.1 × 104 N   s. 
C) 8.0 × 104 N   s. 
D) 5.0 × 105 N   s. 
E) 6.0 × 105 N   s. 
A) 5.1 × 104 N   s. 
B) 6.1 × 104 N   s. 
C) 8.0 × 104 N   s. 
D) 5.0 × 105 N   s. 
E) 6.0 × 105 N   s.

Question 13

The linear density of a rod,in g/m,is given by  
)The rod extends from the origin to x = 0.400 m.What is the location of the center of mass of the rod?

Accepted Answer

A) x = 0.213 m 
B) x = 0.315 m 
C) x = 0.384 m 
D) x = 0.184 m 
E) x = 0.208 m 
A) x = 0.213 m 
B) x = 0.315 m 
C) x = 0.384 m 
D) x = 0.184 m 
E) x = 0.208 m

Question 14

A 3.0-kg ball with an initial velocity of (4  
+ 3  
)m/s collides with a wall and rebounds with a velocity of (−4  
+ 3  
)m/s.What is the impulse exerted on the ball by the wall?

Accepted Answer

A) +24   N   s 
B) −24   N   s 
C) +18   N   s 
D) −18   N   s 
E) +8.0   N   s 
A) +24   N   s 
B) −24   N   s 
C) +18   N   s 
D) −18   N   s 
E) +8.0   N   s

Question 15

A 10-g bullet moving horizontally with a speed of 1.8 km/s strikes and passes through a 5.0-kg block initially at rest on a horizontal frictionless surface.The bullet emerges from the block with a speed of 1.0 km/s.What is the kinetic energy of the block immediately after the bullet emerges?

Accepted Answer

A) 8.0 J 
B) 6.4 J 
C) 5.3 J 
D) 9.4 J 
E) 10 J 
A) 8.0 J 
B) 6.4 J 
C) 5.3 J 
D) 9.4 J 
E) 10 J

Question 16

A 2000-kg truck traveling at a speed of 6.0 m/s makes a 90° turn in a time of 4.0 s and emerges from this turn with a speed of 4.0 m/s.What is the magnitude of the average resultant force on the truck during this turn?

Accepted Answer

A) 4.0 kN 
B) 5.0 kN 
C) 3.6 kN 
D) 6.4 kN 
E) 0.67 kN 
A) 4.0 kN 
B) 5.0 kN 
C) 3.6 kN 
D) 6.4 kN 
E) 0.67 kN

Question 17

A 3.0-kg mass sliding on a frictionless surface has a velocity of 5.0 m/s east when it undergoes a one-dimensional inelastic collision with a 2.0-kg mass that has an initial velocity of 2.0 m/s west.After the collision the 3.0-kg mass has a velocity of 1.0 m/s east.How much kinetic energy does the two-mass system lose during the collision?

Accepted Answer

A) 22 J 
B) 24 J 
C) 26 J 
D) 20 J 
E) 28 J 
A) 22 J 
B) 24 J 
C) 26 J 
D) 20 J 
E) 28 J

Question 18

A 4.2-kg object,initially at rest,"explodes" into three objects of equal mass.Two of these are determined to have velocities of equal magnitudes (5.0 m/s)with directions that differ by 90°.How much kinetic energy was released in the explosion?

Accepted Answer

A) 70 J 
B) 53 J 
C) 60 J 
D) 64 J 
E) 35 J 
A) 70 J 
B) 53 J 
C) 60 J 
D) 64 J 
E) 35 J

Question 19

A 3.0-kg mass moving in the positive x direction with a speed of 10 m/s collides with a 6.0-kg mass initially at rest.After the collision,the speed of the 3.0-kg mass is 8.0 m/s,and its velocity vector makes an angle of 35° with the positive x axis.What is the magnitude of the velocity of the 6.0-kg mass after the collision?

Accepted Answer

A) 2.2 m/s 
B) 2.9 m/s 
C) 4.2 m/s 
D) 3.5 m/s 
E) 4.7 m/s 
A) 2.2 m/s 
B) 2.9 m/s 
C) 4.2 m/s 
D) 3.5 m/s 
E) 4.7 m/s

Question 20

At an instant when a particle of mass 50 g has an acceleration of 80 m/s2 in the positive x direction,a 75-g particle has an acceleration of 40 m/s2 in the positive y direction.What is the magnitude of the acceleration of the center of mass of this two-particle system at this instant?

Accepted Answer

A) 60 m/s2 
B) 56 m/s2 
C) 40 m/s2 
D) 50 m/s2 
E) 46 m/s2 
A) 60 m/s2 
B) 56 m/s2 
C) 40 m/s2 
D) 50 m/s2 
E) 46 m/s2

Exam 9: Linear Momentum and Collisions

A 0.28-kg stone you throw rises 34.3 m in the air.The magnitude of the impulse the stone received from your hand while being thrown is

A 2.0-kg object moving 5.0 m/s collides with and sticks to an 8.0-kg object initially at rest.Determine the kinetic energy lost by the system as a result of this collision.

If you know the impulse that has acted on a body of mass m you can calculate

The only force acting on a 2.0-kg object moving along the x axis is shown.If the velocity vx is −2.0 m/s at t = 0,what is the velocity at t = 4.0 s?

Two boys in a canoe toss a baseball back and forth.What effect will this have on the canoe? Neglect (velocity-dependent)frictional forces with water or air.

Car A rear ends Car B,which has twice the mass of A,on an icy road at a speed low enough so that the collision is essentially elastic.Car B is stopped at a light when it is struck.Car A has mass m and speed v before the collision.After the collision

A 6.0-kg object moving 2.0 m/s in the positive x direction has a one-dimensional elastic collision with a 4.0-kg object moving 3.0 m/s in the opposite direction.What is the total kinetic energy of the two-mass system after the collision?

A 2.0-kg object moving with a velocity of 5.0 m/s in the positive x direction strikes and sticks to a 3.0-kg object moving with a speed of 2.0 m/s in the same direction.How much kinetic energy is lost in this collision?

Two cars start at the same point,but travel in opposite directions on a circular path of radius R,each at speed v.While each car travels a distance less than ,one quarter circle,the center of mass of the two cars

A catapult fires an 800-kg rock with an initial velocity of 100 m/s at a 40° angle to the ground.The magnitude of the vertical impulse the catapult receives from the rock is

The linear density of a rod,in g/m,is given by )The rod extends from the origin to x = 0.400 m.What is the location of the center of mass of the rod?

A 3.0-kg ball with an initial velocity of (4 + 3 )m/s collides with a wall and rebounds with a velocity of (−4 + 3 )m/s.What is the impulse exerted on the ball by the wall?

A 10-g bullet moving horizontally with a speed of 1.8 km/s strikes and passes through a 5.0-kg block initially at rest on a horizontal frictionless surface.The bullet emerges from the block with a speed of 1.0 km/s.What is the kinetic energy of the block immediately after the bullet emerges?

A 2000-kg truck traveling at a speed of 6.0 m/s makes a 90° turn in a time of 4.0 s and emerges from this turn with a speed of 4.0 m/s.What is the magnitude of the average resultant force on the truck during this turn?

A 4.2-kg object,initially at rest,"explodes" into three objects of equal mass.Two of these are determined to have velocities of equal magnitudes (5.0 m/s)with directions that differ by 90°.How much kinetic energy was released in the explosion?

At an instant when a particle of mass 50 g has an acceleration of 80 m/s2 in the positive x direction,a 75-g particle has an acceleration of 40 m/s2 in the positive y direction.What is the magnitude of the acceleration of the center of mass of this two-particle system at this instant?

Physics and Measurement

Motion in One Dimension

Vectors

Motion in Two Dimensions

The Laws of Motion

Circular Motion and Other Applications of Newtons Laws

Energy of a System

Conservation of Energy

Rotation of a Rigid Object About a Fixed Axis

Angular Momentum

Static Equilibrium and Elasticity

Universal Gravitation

Fluid Mechanics

Oscillatory Motion

Wave Motion

Sound Waves

Superposition and Standing Waves

Temperature

The First Law of Thermodynamics

The Kinetic Theory of Gases

Heat Engines, entropy, and the Second Law of Thermodynamics

Electric Fields

Gausss Law

Electric Potential

Capacitance and Dielectrics

Current and Resistance

Direct-Current Circuits

Magnetic Fields

Sources of the Magnetic Field

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Image Formation

Wave Optics

Diffraction Patterns and Polarization

Relativity

Introduction to Quantum Physics

Quantum Mechanics

Atomic Physics

Molecules and Solids

Nuclear Structure

Applications of Nuclear Physics

Particle Physics and Cosmology

Filters

The only force acting on a 2.0-kg object moving along the x axis is shown.If the velocity v_x is −2.0 m/s at t = 0,what is the velocity at t = 4.0 s?

At an instant when a particle of mass 50 g has an acceleration of 80 m/s² in the positive x direction,a 75-g particle has an acceleration of 40 m/s² in the positive y direction.What is the magnitude of the acceleration of the center of mass of this two-particle system at this instant?