Question 1

A 0.28-kg stone you throw rises 34.3 m in the air.The impulse your hand receives from the stone while it throws the stone is

Accepted Answer

A) 2.7 N . s,up. 
B) 2.7 N . s,down. 
C) 7.3 N . s,up. 
D) 7.3 N . s,down. 
E) 9.6 N . s,up. 
A) 2.7 N . s,up. 
B) 2.7 N . s,down. 
C) 7.3 N . s,up. 
D) 7.3 N . s,down. 
E) 9.6 N . s,up. D

Question 2

A steel ball bearing of mass m1 and speed of magnitude v1 has a head-on elastic collision with a steel ball bearing of mass m2 at rest.Rank the speed v1 of m1 relative to v2,the magnitude of the speed of m2,after the collision when i)m1 > m2;ii)m1 = m2;and iii)m1 2.

Accepted Answer

A) v1 2; v1 2; v1 2 
B) v1 2; v1 = v2; v1 > v2 
C) v1 2; v1 > v2; v1 > v2 
D) v1 > v2; v1 = v2; v1 2 
E) v1 > v2; v1 > v2; v1 > v2 
A) v1 2; v1 2; v1 2 
B) v1 2; v1 = v2; v1 > v2 
C) v1 2; v1 > v2; v1 > v2 
D) v1 > v2; v1 = v2; v1 2 
E) v1 > v2; v1 > v2; v1 > v2 B

Question 3

A catapult fires an 800-kg rock with an initial velocity of 100 m/s at a 40$\degree$ angle to the ground.The magnitude of the horizontal 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. B

Question 4

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$\degree$ 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 5

Exhibit 9-1
  
Use this exhibit to answer the following question.
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$\degree$ angle to the ground. 
-Refer to Exhibit 9-1.What is the horizontal component of their momentum,in $\frac { \mathrm { kg } \cdot \mathrm { m } } { \mathrm { s } }$ ,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 6

A 1.2-kg object moving with a speed of 8.0 m/s collides perpendicularly with a wall and emerges with a speed of 6.0 m/s in the opposite direction.If the object is in contact with the wall for 2.0 ms,what is the magnitude of the average force on the object by the wall?

Accepted Answer

A) 9.8 kN 
B) 8.4 kN 
C) 7.7 kN 
D) 9.1 kN 
E) 1.2 kN 
A) 9.8 kN 
B) 8.4 kN 
C) 7.7 kN 
D) 9.1 kN 
E) 1.2 kN

Question 7

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 $\frac { \pi } { 2 } \mathrm { R }$ ,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 8

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$\degree$.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 9

A 4.0-kg mass has a velocity of 4.0 m/s,east when it explodes into two 2.0-kg masses.After the explosion one of the masses has a velocity of 3.0 m/s at an angle of 60$\degree$ north of east.What is the magnitude of the velocity of the other mass after the explosion?

Accepted Answer

A) 7.9 m/s 
B) 8.9 m/s 
C) 7.0 m/s 
D) 6.1 m/s 
E) 6.7 m/s 
A) 7.9 m/s 
B) 8.9 m/s 
C) 7.0 m/s 
D) 6.1 m/s 
E) 6.7 m/s

Question 10

A 1.5-kg playground ball is moving with a velocity of 3.0 m/s directed 30$\degree$ below the horizontal just before it strikes a horizontal surface.The ball leaves this surface 0.50 s later with a velocity of 2.0 m/s directed 60$\degree$ above the horizontal.What is the magnitude of the average resultant force on the ball?

Accepted Answer

A) 14 N 
B) 11 N 
C) 18 N 
D) 22 N 
E) 3.0 N 
A) 14 N 
B) 11 N 
C) 18 N 
D) 22 N 
E) 3.0 N

Question 11

Assume that the average mass of each of the approximately 1 billion people in China is 55 kg.Assume that they all gather in one place and climb to the top of 2 m high ladders.The center of mass of the Earth (mE = 5.90 $x$ 1024 kg)is then displaced

Accepted Answer

A) 0 m. 
B) 1.84*10-23 m. 
C) 1.84 *10-14 m. 
D) 1.80 *10-13 m. 
E) 2 m. 
A) 0 m. 
B) 1.84*10-23 m. 
C) 1.84 *10-14 m. 
D) 1.80 *10-13 m. 
E) 2 m.

Question 12

When the rate of burn and the exhaust velocity are constant,a rocket ascends with

Accepted Answer

A) decreasing acceleration. 
B) decreasing velocity. 
C) constant velocity. 
D) constant acceleration. 
E) increasing acceleration. 
A) decreasing acceleration. 
B) decreasing velocity. 
C) constant velocity. 
D) constant acceleration. 
E) increasing acceleration.

Question 13

A 3.00-kg stone is dropped from a 39.2 m high building.When the stone has fallen 19.6 m,the magnitude of the impulse it has received from the gravitational force is

Accepted Answer

A) 9.80 N . s. 
B) 19.6 N . s. 
C) 29.4 N . s. 
D) 58.8 N . s. 
E) 118 N . s. 
A) 9.80 N . s. 
B) 19.6 N . s. 
C) 29.4 N . s. 
D) 58.8 N . s. 
E) 118 N . s.

Question 14

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 15

A 12-g bullet moving horizontally strikes and remains in a 3.0-kg block initially at rest on the edge of a table.The block,which is initially 80 cm above the floor,strikes the floor a horizontal distance of 120 cm from its initial position.What was the initial speed of the bullet?

Accepted Answer

A) 0.68 km/s 
B) 0.75 km/s 
C) 0.81 km/s 
D) 0.87 km/s 
E) 0.41 km/s 
A) 0.68 km/s 
B) 0.75 km/s 
C) 0.81 km/s 
D) 0.87 km/s 
E) 0.41 km/s

Question 16

The linear density of a rod,in g/m,is given by $\lambda = 40.0 + 30.0 x$ .The rod extends from the origin to x = 0.400 m.What is the mass of the rod?

Accepted Answer

A) 0.213 g 
B) 3.50 g 
C) 3.84 g 
D) 18.4 g 
E) 20.8 g 
A) 0.213 g 
B) 3.50 g 
C) 3.84 g 
D) 18.4 g 
E) 20.8 g

Question 17

A 3.0-kg object moving in the positive x direction has a one-dimensional elastic collision with a 5.0-kg object initially at rest.After the collision the 5.0-kg object has a velocity of 6.0 m/s in the positive x direction.What was the initial speed of the 3.0 kg object?

Accepted Answer

A) 6.0 m/s 
B) 7.0 m/s 
C) 4.5 m/s 
D) 8.0 m/s 
E) 5.5 m/s 
A) 6.0 m/s 
B) 7.0 m/s 
C) 4.5 m/s 
D) 8.0 m/s 
E) 5.5 m/s

Question 18

An astronaut outside a spaceship hammers a loose rivet back in place.What happens to the astronaut as he swings the hammer?

Accepted Answer

A) Nothing.The spaceship takes up the momentum of the hammer. 
B) He moves away from the spaceship. 
C) He moves towards the spaceship. 
D) He moves towards the spaceship as he pulls the hammer back and moves away from it as he swings the hammer forward. 
E) He moves away from the spaceship as he pulls the hammer back and moves toward it as he swings the hammer forward. 
A) Nothing.The spaceship takes up the momentum of the hammer. 
B) He moves away from the spaceship. 
C) He moves towards the spaceship. 
D) He moves towards the spaceship as he pulls the hammer back and moves away from it as he swings the hammer forward. 
E) He moves away from the spaceship as he pulls the hammer back and moves toward it as he swings the hammer forward.

Question 19

A 1.6-kg ball is attached to the end of a 0.40-m string to form a pendulum.This pendulum is released from rest with the string horizontal.At the lowest point of its swing,when it is moving horizontally,the ball collides with a 0.80-kg block initially at rest on a horizontal frictionless surface.The speed of the block just after the collision is 3.0 m/s.What is the speed of the ball just after the collision?

Accepted Answer

A) 1.7 m/s 
B) 1.1 m/s 
C) 1.5 m/s 
D) 1.3 m/s 
E) 2.1 m/s 
A) 1.7 m/s 
B) 1.1 m/s 
C) 1.5 m/s 
D) 1.3 m/s 
E) 2.1 m/s

Question 20

Two bodies of equal mass m collide and stick together.The quantities that always have equal magnitude for both masses during the collision are

Accepted Answer

A) their changes in momentum. 
B) the force each exerts on the other. 
C) their changes in kinetic energy. 
D) all of the above. 
E) only (a)and (b)above. 
A) their changes in momentum. 
B) the force each exerts on the other. 
C) their changes in kinetic energy. 
D) all of the above. 
E) only (a)and (b)above.

Exam 8: Momentum and Collisions

A 0.28-kg stone you throw rises 34.3 m in the air.The impulse your hand receives from the stone while it throws the stone is

A steel ball bearing of mass m1 and speed of magnitude v1 has a head-on elastic collision with a steel ball bearing of mass m2 at rest.Rank the speed v1 of m1 relative to v2,the magnitude of the speed of m2,after the collision when i)m1 > m2;ii)m1 = m2;and iii)m1 < m2.

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

A 1.2-kg object moving with a speed of 8.0 m/s collides perpendicularly with a wall and emerges with a speed of 6.0 m/s in the opposite direction.If the object is in contact with the wall for 2.0 ms,what is the magnitude of the average force on the object by the wall?

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 π2R\frac { \pi } { 2 } \mathrm { R }2π​R ,one quarter circle,the center of mass of the two cars

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 °\degree° .How much kinetic energy was released in the explosion?

A 4.0-kg mass has a velocity of 4.0 m/s,east when it explodes into two 2.0-kg masses.After the explosion one of the masses has a velocity of 3.0 m/s at an angle of 60 °\degree° north of east.What is the magnitude of the velocity of the other mass after the explosion?

Assume that the average mass of each of the approximately 1 billion people in China is 55 kg.Assume that they all gather in one place and climb to the top of 2 m high ladders.The center of mass of the Earth (mE = 5.90 xxx 1024 kg)is then displaced

When the rate of burn and the exhaust velocity are constant,a rocket ascends with

A 3.00-kg stone is dropped from a 39.2 m high building.When the stone has fallen 19.6 m,the magnitude of the impulse it has received from the gravitational force is

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?

A 12-g bullet moving horizontally strikes and remains in a 3.0-kg block initially at rest on the edge of a table.The block,which is initially 80 cm above the floor,strikes the floor a horizontal distance of 120 cm from its initial position.What was the initial speed of the bullet?

The linear density of a rod,in g/m,is given by λ=40.0+30.0x\lambda = 40.0 + 30.0 xλ=40.0+30.0x .The rod extends from the origin to x = 0.400 m.What is the mass of the rod?

A 3.0-kg object moving in the positive x direction has a one-dimensional elastic collision with a 5.0-kg object initially at rest.After the collision the 5.0-kg object has a velocity of 6.0 m/s in the positive x direction.What was the initial speed of the 3.0 kg object?

An astronaut outside a spaceship hammers a loose rivet back in place.What happens to the astronaut as he swings the hammer?

Two bodies of equal mass m collide and stick together.The quantities that always have equal magnitude for both masses during the collision are

Introduction and Vectors

Motion in One Dimension

Motion in Two Dimensions

The Laws of Motion

More Applications of Newtons Laws

Energy of a System

Conservation of Energy

Relativity

Rotational Motion

Gravity,planetary Orbits,and the Hydrogen Atom

Oscillatory Motion

Mechanical Waves

Superposition and Standing Waves

Fluid Mechanics

Temperature and the Kinetic Theory of Gases

Energy in Thermal Processes: the First Law of Thermodynamics

Heat Engines,entropy,and the Second Law of Thermodynamics

Electric Forces and Electric Fields

Electric Potential and Capacitance

Current and Direct Current Circuits

Magnetic Forces and Magnetic Fields

Faradays Law and Inductance

Electromagnetic Waves

Reflection and Refraction of Light

Image Formation by Mirrors and Lenses

Wave Optics

Quantum Physics

Atomic Physics

Nuclear Physics

Particle Physics

Filters

A steel ball bearing of mass m₁ and speed of magnitude v₁ has a head-on elastic collision with a steel ball bearing of mass m₂ at rest.Rank the speed v₁ of m₁ relative to v₂,the magnitude of the speed of m₂,after the collision when i)m₁ > m₂;ii)m₁ = m₂;and iii)m₁ < m₂.

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

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 $\frac { \pi } { 2 } \mathrm { R }$ ,one quarter circle,the center of mass of the two cars

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 $\degree$ .How much kinetic energy was released in the explosion?

A 4.0-kg mass has a velocity of 4.0 m/s,east when it explodes into two 2.0-kg masses.After the explosion one of the masses has a velocity of 3.0 m/s at an angle of 60 $\degree$ north of east.What is the magnitude of the velocity of the other mass after the explosion?

Assume that the average mass of each of the approximately 1 billion people in China is 55 kg.Assume that they all gather in one place and climb to the top of 2 m high ladders.The center of mass of the Earth (m_E = 5.90 $x$ 10²⁴ kg)is then displaced

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?

The linear density of a rod,in g/m,is given by $\lambda = 40.0 + 30.0 x$ .The rod extends from the origin to x = 0.400 m.What is the mass of the rod?