Question 1

Three boxes slide on a frictionless horizontal surface when pulled by a force of magnitude F. When we compare the tensions T1 and T2 with the force F, we find that

Accepted Answer

A)  T1 = T2 = F. 
B)  T1 = F > T2. 
C)  F > T1 = T2. 
D)  F > T1 > T2. 
E)  F − T1 1 − T2. 
A)  T1 = T2 = F. 
B)  T1 = F > T2. 
C)  F > T1 = T2. 
D)  F > T1 > T2. 
E)  F − T1 1 − T2.

Question 2

An 8.0-kg object rests on the floor of an elevator which is accelerating downward at a rate of 1.3 m/s2. What is the magnitude of the force the object exerts on the floor of the elevator?

Accepted Answer

A)  59 N 
B)  10 N 
C)  89 N 
D)  68 N 
E)  78 N 
A)  59 N 
B)  10 N 
C)  89 N 
D)  68 N 
E)  78 N

Question 3

Two people, each of 70 kg mass, are riding in an elevator. One is standing on the floor. The other is hanging on a rope suspended from the ceiling. Compare the force   the floor exerts on the first person to the force   the rope exerts on the second person. Which statement is correct?

Accepted Answer

A)  They are equal and opposite in direction. 
B)  They are equal and have the same direction. 
C) 
  is greater than
  , but they have the same direction. 
D) 
  is greater than
  , but they have opposite directions. 
E) 
  is less than
  , but they have the same direction. 
A)  They are equal and opposite in direction. 
B)  They are equal and have the same direction. 
C) 
  is greater than
  , but they have the same direction. 
D) 
  is greater than
  , but they have opposite directions. 
E) 
  is less than
  , but they have the same direction.

Question 4

The tension in a string from which a 4.0-kg object is suspended in an elevator is equal to 44 N. What is the acceleration of the elevator?

Accepted Answer

A)  11 m/s2 upward 
B)  1.2 m/s2 upward 
C)  1.2 m/s2 downward 
D)  10 m/s2 upward 
E)  2.4 m/s2 downward 
A)  11 m/s2 upward 
B)  1.2 m/s2 upward 
C)  1.2 m/s2 downward 
D)  10 m/s2 upward 
E)  2.4 m/s2 downward

Question 5

If M = 1.1 kg, what is the tension in string 1?

Accepted Answer

A)  54 N 
B)  47 N 
C)  40 N 
D)  62 N 
E)  57 N 
A)  54 N 
B)  47 N 
C)  40 N 
D)  62 N 
E)  57 N

Question 6

You have a machine which can accelerate pucks on frictionless ice. Starting from rest, the puck travels a distance x in time t when force F is applied. If force 3F is applied, the distance the puck travels in time t is

Accepted Answer

A)  x. 
B)  (3/2)x. 
C)  3x. 
D)  (9/2)x. 
E)  9x. 
A)  x. 
B)  (3/2)x. 
C)  3x. 
D)  (9/2)x. 
E)  9x.

Question 7

A 2000-kg sailboat experiences an eastward force of 3000 N by the ocean tide and a wind force against its sails of magnitude 6000 N directed toward the northwest (45° N of W). What is the magnitude and direction of the resultant acceleration?

Accepted Answer

2.2 m/s² at

Question 8

Two experiments are performed. In (A), an 18.0 N force pushes horizontally on a 2.00 kg block that then pushes on a 4.00 kg block. In (B), an 18.0 N force pushes on a 4.00 kg block that then pushes on a 2.00 kg block. Which statement is correct?

Accepted Answer

A)  The acceleration is 3.00 m/s2 in both (
A)  and (
B) . 
B)  The acceleration is 4.50 m/s2 in both (
A)  and (
B) . 
C)  The acceleration is 6.00 m/s2 in both (
A)  and (
B) . 
D)  The acceleration is 9.00 m/s2 in both (
A)  and (
B) . 
E)  The 2.00 kg block has a 9.00 m/s2 acceleration. The 4.00 kg block has a 4.50 m/s2 acceleration. 
A)  The acceleration is 3.00 m/s2 in both (
A)  and (
B) . 
B)  The acceleration is 4.50 m/s2 in both (
A)  and (
B) . 
C)  The acceleration is 6.00 m/s2 in both (
A)  and (
B) . 
D)  The acceleration is 9.00 m/s2 in both (
A)  and (
B) . 
E)  The 2.00 kg block has a 9.00 m/s2 acceleration. The 4.00 kg block has a 4.50 m/s2 acceleration.

Question 9

A 4.0-kg block slides down a 35° incline at a constant speed when a 16-N force is applied acting up and parallel to the incline. What is the coefficient of kinetic friction between the block and the surface of the incline?

Accepted Answer

A)  0.20 
B)  0.23 
C)  0.26 
D)  0.33 
E)  0.41 
A)  0.20 
B)  0.23 
C)  0.26 
D)  0.33 
E)  0.41

Question 10

A bumper car is moving at constant velocity when another bumper car starts to push on it with a constant force at an angle of 60 degrees with respect to the first car's initial velocity. The second bumper car continues pushing in exactly that direction for some time. What is most likely to happen is that

Accepted Answer

A)  the first car will stop moving. 
B)  the first car will move in the direction of the force. 
C)  the first car's velocity will increase in magnitude but not change direction. 
D)  the first car's velocity will gradually change direction more and more toward that of the force while increasing in magnitude. 
E)  the first car's velocity will gradually change direction more and more toward that of the force while decreasing in magnitude. 
A)  the first car will stop moving. 
B)  the first car will move in the direction of the force. 
C)  the first car's velocity will increase in magnitude but not change direction. 
D)  the first car's velocity will gradually change direction more and more toward that of the force while increasing in magnitude. 
E)  the first car's velocity will gradually change direction more and more toward that of the force while decreasing in magnitude.

Question 11

A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s2 upward?

Accepted Answer

A)  69 N downward 
B)  29 N downward 
C)  49 N downward 
D)  20 N downward 
E)  19 N downward 
A)  69 N downward 
B)  29 N downward 
C)  49 N downward 
D)  20 N downward 
E)  19 N downward

Question 12

A juggler throws two balls up to the same height so that they pass each other halfway up when A is rising and B is descending. Ignore air resistance and buoyant forces. Which statement is true of the two balls at that point?

Accepted Answer

A)  There is an residual upward force from the hand on each ball. 
B)  There is a greater residual force from the hand on A than there is on B. 
C)  Only gravity acts on B but there is an additional residual force from the hand on A. 
D)  There is an additional downwards force besides gravity on each ball. 
E)  The only force acting on each ball is the gravitational force. 
A)  There is an residual upward force from the hand on each ball. 
B)  There is a greater residual force from the hand on A than there is on B. 
C)  Only gravity acts on B but there is an additional residual force from the hand on A. 
D)  There is an additional downwards force besides gravity on each ball. 
E)  The only force acting on each ball is the gravitational force.

Question 13

The horizontal surface on which the objects slide is frictionless. If M = 2.0 kg, the tension in string 1 is 12 N. Determine F.

Accepted Answer

A)  25 N 
B)  20 N 
C)  30 N 
D)  35 N 
E)  40 N 
A)  25 N 
B)  20 N 
C)  30 N 
D)  35 N 
E)  40 N

Exam 5: The Laws of Motion

Three boxes slide on a frictionless horizontal surface when pulled by a force of magnitude F. When we compare the tensions T1 and T2 with the force F, we find that

An 8.0-kg object rests on the floor of an elevator which is accelerating downward at a rate of 1.3 m/s2. What is the magnitude of the force the object exerts on the floor of the elevator?

Two people, each of 70 kg mass, are riding in an elevator. One is standing on the floor. The other is hanging on a rope suspended from the ceiling. Compare the force the floor exerts on the first person to the force the rope exerts on the second person. Which statement is correct?

The tension in a string from which a 4.0-kg object is suspended in an elevator is equal to 44 N. What is the acceleration of the elevator?

If M = 1.1 kg, what is the tension in string 1?

You have a machine which can accelerate pucks on frictionless ice. Starting from rest, the puck travels a distance x in time t when force F is applied. If force 3F is applied, the distance the puck travels in time t is

A 2000-kg sailboat experiences an eastward force of 3000 N by the ocean tide and a wind force against its sails of magnitude 6000 N directed toward the northwest (45° N of W). What is the magnitude and direction of the resultant acceleration?

Two experiments are performed. In (A), an 18.0 N force pushes horizontally on a 2.00 kg block that then pushes on a 4.00 kg block. In (B), an 18.0 N force pushes on a 4.00 kg block that then pushes on a 2.00 kg block. Which statement is correct?

A 4.0-kg block slides down a 35° incline at a constant speed when a 16-N force is applied acting up and parallel to the incline. What is the coefficient of kinetic friction between the block and the surface of the incline?

A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s2 upward?

A juggler throws two balls up to the same height so that they pass each other halfway up when A is rising and B is descending. Ignore air resistance and buoyant forces. Which statement is true of the two balls at that point?

The horizontal surface on which the objects slide is frictionless. If M = 2.0 kg, the tension in string 1 is 12 N. Determine F.

Physics and Measurement

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Circular Motion and Other Applications of Newtons Laws

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Conservation of Energy

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Universal Gravitation

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Introduction to Quantum Physics

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Filters

Three boxes slide on a frictionless horizontal surface when pulled by a force of magnitude F. When we compare the tensions T₁ and T₂ with the force F, we find that

An 8.0-kg object rests on the floor of an elevator which is accelerating downward at a rate of 1.3 m/s². What is the magnitude of the force the object exerts on the floor of the elevator?

A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s² upward?