Question 1

A sports car of mass 1000 kg can accelerate from rest to 72. km/h in 6.6 s. What would the average force of the car's engine be?

Accepted Answer

The answer of A sports car of mass 1000 kg...

Question 2

Your mass on the moon will be about one-sixth of your mass on Earth.

Accepted Answer

A) True 
 B)False

Question 3

A rope, tied between a motor and a crate, can pull the crate up a hill of ice (assume no friction) Figure 4-6
   
The free-body diagram of the crate should contain how many force(s)? Identify them.

Accepted Answer

Three forces: the we

Question 4

The coefficients of friction for plastic on wood are ?s = 0.50 and ?k = 0.40. How much horizontal force would you need to apply to a 3.0-lb plastic calculator to start it moving from rest?

Accepted Answer

A)  1.2 N 
B)  2.7 N 
C)  0.50 N 
D)  0.15 N 
E)  6.7 N 
A)  1.2 N 
B)  2.7 N 
C)  0.50 N 
D)  0.15 N 
E)  6.7 N

Question 5

What is the weight of a 14.0 kg pumpkin in Newtons?

Accepted Answer

The answer of What is the weight of a 14.0...

Question 6

Two cardboard boxes full of books are in contact with each other on a table, as shown in Figure 4-4. Box H has twice the mass of box G.
 
If you push on box G with a horizontal force F, then box H will experience a net force of

Accepted Answer

A)  F. 
B)  2 F. 
C)  3 F. 
D)  2/3 F. 
E)  3/2 F. 
A)  F. 
B)  2 F. 
C)  3 F. 
D)  2/3 F. 
E)  3/2 F.

Question 7

Planning to elope with her boyfriend, Janice slides down a rope from her fourth story window. As she slides down the rope, she tightens harder on the rope which of course increases the tension in the rope. When the upward tension in the rope equals Janice's weight

Accepted Answer

A)  Janice will speed up. 
B)  Janice will continue down at constant speed. 
C)  the rope will break. 
D)  Janice will slow down. 
E)  Janice will stop moving down the rope. 
A)  Janice will speed up. 
B)  Janice will continue down at constant speed. 
C)  the rope will break. 
D)  Janice will slow down. 
E)  Janice will stop moving down the rope.

Question 8

A 170. pound halfback is tackled by a 245. pound guard. Each, of course, exerts a force on the other. Which of the players exerts the LARGER force on the other?

Accepted Answer

neither (N

Question 9

An automobile initially moving 72. km/hr jams the brakes and skids to a stop in a distance of 24. meters on a dry pavement but stops in 81.6 m for a wet pavement (the auto weighs 2211.lbs; neglect reaction delay) 
(a) What is the coefficient of friction for dry weather?
(b) What is the coefficient in wet weather conditions?
(c) Is this the STATIC or the KINETIC coefficient?

Accepted Answer

(a) 0.85
(

Question 10

A horizontal force of 5.0 N accelerates a 4.0 kg mass, from rest, at a rate of
0)50 m/ s2 in the positive direction. What friction force acts on the mass?

Accepted Answer

A)  +3.0 N 
B)  -2.0 N 
C)  -3.3 N 
D)  -3.0 N 
E)  +2.0 N 
A)  +3.0 N 
B)  -2.0 N 
C)  -3.3 N 
D)  -3.0 N 
E)  +2.0 N

Question 11

During the investigation of a traffic accident, police find skid marks 90 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.50 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

Accepted Answer

The answer of During the investigation of a traffic accident,...

Question 12

Two toy cars (16 kg and 2 kg) are released simultaneously on an inclined plane that makes an angle of 30° with the horizontal. Which statement best describes their acceleration after being released?

Accepted Answer

A)  The 16-kg car accelerates 8 times faster than the 2-kg car. 
B)  Both cars accelerate at a rate of g sin(30°). 
C)  Both cars accelerate at a rate of 0.866 g. 
D)  The 2-kg car accelerates 8 times faster than the 16-kg car. 
E)  Both cars accelerate at a rate of 8?g. 
A)  The 16-kg car accelerates 8 times faster than the 2-kg car. 
B)  Both cars accelerate at a rate of g sin(30°). 
C)  Both cars accelerate at a rate of 0.866 g. 
D)  The 2-kg car accelerates 8 times faster than the 16-kg car. 
E)  Both cars accelerate at a rate of 8?g.

Question 13

Stacy (S) and David (D) are having a tug-of-war by pulling on opposite ends of a 5.0 kg rope. Stacy pulls with a 15. N force. What is David's force if the rope accelerates toward Stacy at 2.0 m/ s2?

Accepted Answer

A)  15 N 
B)  3 N 
C)  50 N 
D)  5 N 
E)  25 N 
A)  15 N 
B)  3 N 
C)  50 N 
D)  5 N 
E)  25 N

Question 14

A 10. kg blocks rests on a table (on Earth) Figure 4-9
   
If someone pushes down on the block with a 48. Newton force, what is the maximum horizontal pull (P) that will not move the block?

Accepted Answer

The answer of A 10. kg blocks rests on a...

Question 15

See Figure 4.1. If two identical masses are attached by a light cord passing over a massless, frictionless pulley of an Atwood's machine, but at different heights, and then released, then

Accepted Answer

A)  the lower mass will go down. 
B)  the motion will depend on the amount of the masses. 
C)  the higher mass will go down. 
D)  the masses will not move. 
A)  the lower mass will go down. 
B)  the motion will depend on the amount of the masses. 
C)  the higher mass will go down. 
D)  the masses will not move.

Question 16

Use the Figure 4-11 and the information below to answer the following question(s).
A train consists of a caboose (mass = 1000 kg), a car (mass 2000 kg), and an engine car (mass 2000 kg).
  
-Refer to Figure 4-11. The wheels of the engine are pushing back with what force?

Accepted Answer

A)  16.5 kN 
B)  5.50 kN 
C)  27.5 kN 
D)  11.0 kN 
E)  550. N 
A)  16.5 kN 
B)  5.50 kN 
C)  27.5 kN 
D)  11.0 kN 
E)  550. N

Question 17

A 1300. N gondola car, at a ski lift, is temporarily suspended at the halfway point, causing the wire to sag by 37.0° below the horizontal, as shown in Figure 4-10.
 
 The tension in the cable is

Accepted Answer

A)  4.32 × 103 N 
B)  1.63 × 103 N 
C)  2.16 × 103 N 
D)  8.14 × 102 N 
E)  1.08 × 102 N 
A)  4.32 × 103 N 
B)  1.63 × 103 N 
C)  2.16 × 103 N 
D)  8.14 × 102 N 
E)  1.08 × 102 N

Question 18

A wooden block slides directly down an inclined plane, at a constant velocity of 6.0 m/s. How large is the coefficient of kinetic friction, ?k, if the plane makes an angle of 25.° with the horizontal?

Accepted Answer

A)  1.2 
B)  0.37 
C)  0.42 
D)  0.91 
E)  0.47 
A)  1.2 
B)  0.37 
C)  0.42 
D)  0.91 
E)  0.47

Question 19

State Newton's 3rd law in your own words.

Accepted Answer

For every force (act

Question 20

Use the Figure 4-11 and the information below to answer the following question(s).
A train consists of a caboose (mass = 1000 kg), a car (mass 2000 kg), and an engine car (mass 2000 kg).
  
-Refer to Figure 4-11. If the train has an acceleration of 5.50 m/s2, then the tension force in the coupling between the middle car and the engine car is

Accepted Answer

A)  16.5 kN. 
B)  27.5 kN. 
C)  5.50 kN. 
D)  11.0 kN. 
E)  8.25 kN. 
A)  16.5 kN. 
B)  27.5 kN. 
C)  5.50 kN. 
D)  11.0 kN. 
E)  8.25 kN.

Exam 4: Force and Motion

A sports car of mass 1000 kg can accelerate from rest to 72. km/h in 6.6 s. What would the average force of the car's engine be?

Your mass on the moon will be about one-sixth of your mass on Earth.

A rope, tied between a motor and a crate, can pull the crate up a hill of ice (assume no friction) Figure 4-6 The free-body diagram of the crate should contain how many force(s)? Identify them.

The coefficients of friction for plastic on wood are ?s = 0.50 and ?k = 0.40. How much horizontal force would you need to apply to a 3.0-lb plastic calculator to start it moving from rest?

What is the weight of a 14.0 kg pumpkin in Newtons?

Two cardboard boxes full of books are in contact with each other on a table, as shown in Figure 4-4. Box H has twice the mass of box G. If you push on box G with a horizontal force F, then box H will experience a net force of

Planning to elope with her boyfriend, Janice slides down a rope from her fourth story window. As she slides down the rope, she tightens harder on the rope which of course increases the tension in the rope. When the upward tension in the rope equals Janice's weight

A 170. pound halfback is tackled by a 245. pound guard. Each, of course, exerts a force on the other. Which of the players exerts the LARGER force on the other?

A horizontal force of 5.0 N accelerates a 4.0 kg mass, from rest, at a rate of 0)50 m/ s2 in the positive direction. What friction force acts on the mass?

During the investigation of a traffic accident, police find skid marks 90 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.50 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

Two toy cars (16 kg and 2 kg) are released simultaneously on an inclined plane that makes an angle of 30° with the horizontal. Which statement best describes their acceleration after being released?

Stacy (S) and David (D) are having a tug-of-war by pulling on opposite ends of a 5.0 kg rope. Stacy pulls with a 15. N force. What is David's force if the rope accelerates toward Stacy at 2.0 m/ s2?

A 10. kg blocks rests on a table (on Earth) Figure 4-9 If someone pushes down on the block with a 48. Newton force, what is the maximum horizontal pull (P) that will not move the block?

See Figure 4.1. If two identical masses are attached by a light cord passing over a massless, frictionless pulley of an Atwood's machine, but at different heights, and then released, then

Use the Figure 4-11 and the information below to answer the following question(s). A train consists of a caboose (mass = 1000 kg), a car (mass 2000 kg), and an engine car (mass 2000 kg). -Refer to Figure 4-11. The wheels of the engine are pushing back with what force?

A 1300. N gondola car, at a ski lift, is temporarily suspended at the halfway point, causing the wire to sag by 37.0° below the horizontal, as shown in Figure 4-10. The tension in the cable is

A wooden block slides directly down an inclined plane, at a constant velocity of 6.0 m/s. How large is the coefficient of kinetic friction, ?k, if the plane makes an angle of 25.° with the horizontal?

State Newton's 3rd law in your own words.

Measurement and Problem Solving

Kinematics: Description of Motion

Motion in Two Dimensions

Work and Energy

Linear Momentum and Collisions

Circular Motion and Gravitation

Rotational Motion and Equilibrium

Solids and Fluids

Temperature and Kinetic Theory

Heat

Thermodynamics

Vibrations and Waves

Sound

Electric Charge, Forces, and Fields

Electric Potential, Energy, and Capacitance

Electric Current and Resistance

Basic Electric Circuits

Magnetism

Electromagnetic Induction and Waves

AC Circuits

Reflection and Refraction of Light

Mirrors and Lenses

Physical Optics: The Wave Nature of Light

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Relativity

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The coefficients of friction for plastic on wood are ?_s = 0.50 and ?_k = 0.40. How much horizontal force would you need to apply to a 3.0-lb plastic calculator to start it moving from rest?

A horizontal force of 5.0 N accelerates a 4.0 kg mass, from rest, at a rate of 0)50 m/ s² in the positive direction. What friction force acts on the mass?

Stacy (S) and David (D) are having a tug-of-war by pulling on opposite ends of a 5.0 kg rope. Stacy pulls with a 15. N force. What is David's force if the rope accelerates toward Stacy at 2.0 m/ s²?

A wooden block slides directly down an inclined plane, at a constant velocity of 6.0 m/s. How large is the coefficient of kinetic friction, ?_k, if the plane makes an angle of 25.° with the horizontal?