Question 1

The net force on a moving object suddenly becomes zero. The object then

Accepted Answer

A)  stops abruptly. 
B)  stops during a short time interval. 
C)  changes direction. 
D)  continues at constant velocity. 
E)  slows down gradually. 
A)  stops abruptly. 
B)  stops during a short time interval. 
C)  changes direction. 
D)  continues at constant velocity. 
E)  slows down gradually.

Question 2

A 1.7 kg model airplane is flying north at 12.5 m/s initially, and 25 seconds later is observed heading 30 degrees west of north at 25 m/s. What is the magnitude of the average net force on the airplane during this time interval?

Accepted Answer

A)  0.85 N 
B)  0.63 N 
C)  1.1 N 
D)  1.5 N 
A)  0.85 N 
B)  0.63 N 
C)  1.1 N 
D)  1.5 N

Question 3

A box is pushed across a horizontal table at a constant speed. Of the forces acting, which pair do we know are equal in magnitude because of Newton's third law?

Accepted Answer

A)  The normal force on the box and the weight of the box. 
B)  The normal force on the box and the normal force on the table from the box. 
C)  The force of kinetic friction on the box and the external pushing force applied to the box. 
D)  None of these are interaction pairs. 
A)  The normal force on the box and the weight of the box. 
B)  The normal force on the box and the normal force on the table from the box. 
C)  The force of kinetic friction on the box and the external pushing force applied to the box. 
D)  None of these are interaction pairs.

Question 4

A tractor of mass M1 = 2,000 kg is pulling a trailer of mass M2 = 5,000 kg. If the tractor-trailer is accelerated at 2.0 m/s2, and air resistance is negligible, then the magnitude of the force the tractor applies to the road is

Accepted Answer

A)  14,000 N. 
B)  12,000 N. 
C)  10,000 N. 
D)  8,000 N. 
E)  6,000 N. 
A)  14,000 N. 
B)  12,000 N. 
C)  10,000 N. 
D)  8,000 N. 
E)  6,000 N.

Question 5

When an object is in translational equilibrium, which of these statements is not true?

Accepted Answer

A)  The vector sum of the forces acting on the object is zero. 
B)  The object must be stationary. 
C)  The object has a constant velocity. 
D)  The speed of the object is a constant. 
A)  The vector sum of the forces acting on the object is zero. 
B)  The object must be stationary. 
C)  The object has a constant velocity. 
D)  The speed of the object is a constant.

Question 6

An 80.0 kg person is riding in an elevator that is accelerating at 2.40 m/s2 downward. The apparent weight of the 80.0 kg person measured on a scale in the elevator is

Accepted Answer

A)  592 N. 
B)  639 N. 
C)  784 N. 
D)  855 N. 
E)  976 N. 
A)  592 N. 
B)  639 N. 
C)  784 N. 
D)  855 N. 
E)  976 N.

Question 7

An airplane is flying in horizontal flight at a constant velocity. The weight of the airplane is 40,000 N. The wings produce a lift force that is perpendicular to the wings and a drag force that is parallel to the wings. The engine produces a forward thrust force of 2,000 N. Which of the following statements is true?

Accepted Answer

A)  The net force on the airplane is zero. 
B)  The net force on the airplane is forward. 
C)  The net force on the airplane is upward. 
D)  The net force on the airplane is downward. 
E)  The net force on the airplane is backward. 
A)  The net force on the airplane is zero. 
B)  The net force on the airplane is forward. 
C)  The net force on the airplane is upward. 
D)  The net force on the airplane is downward. 
E)  The net force on the airplane is backward.

Question 8

A tractor T is pulling two trailers, M1 and M2, with a constant acceleration. T has a mass of 200 kg, M1 has a mass of 100 kg, and M2 has a mass of 150 kg. If the forward acceleration is 0.60 m/s2, and air resistance is negligible, then the horizontal force on the tractor due to the attachment to M1 is

Accepted Answer

A)  270 N backward. 
B)  270 N forward. 
C)  150 N backward. 
D)  150 N forward. 
E)  90 N forward. 
A)  270 N backward. 
B)  270 N forward. 
C)  150 N backward. 
D)  150 N forward. 
E)  90 N forward.

Question 9

Within a given system, the internal forces

Accepted Answer

A)  are always balanced by the external forces. 
B)  all add to zero. 
C)  are only determined by subtracting the external forces from the net force on the system. 
D)  determine the motion of the system. 
E)  are measured with a gravimeter. 
A)  are always balanced by the external forces. 
B)  all add to zero. 
C)  are only determined by subtracting the external forces from the net force on the system. 
D)  determine the motion of the system. 
E)  are measured with a gravimeter.

Question 10

The gravitational field at the Earth due to the Moon is about (G = 6.67 × 10-11 N m2/kg2, the mass of the Moon is 7.35 × 1022 kg, and the distance to the Moon is 3.85 × 108 m)

Accepted Answer

A)  2.90 × 10-5 N/kg away from the Moon. 
B)  3.31 × 10-5 N/kg toward the Moon. 
C)  4.01 × 10-5 N/kg toward the Moon. 
D)  3.31 × 10-5 N/kg away from the Moon. 
E)  7.50 × 10-5 N/kg away from the Moon. 
A)  2.90 × 10-5 N/kg away from the Moon. 
B)  3.31 × 10-5 N/kg toward the Moon. 
C)  4.01 × 10-5 N/kg toward the Moon. 
D)  3.31 × 10-5 N/kg away from the Moon. 
E)  7.50 × 10-5 N/kg away from the Moon.

Question 11

What is the gravitational field strength at the location of a satellite that is orbiting the Earth at an altitude of 5,000 km? (G = 6.67 × 10-11 N m2/kg2, the mass of the Earth is 5.98 × 1024 kg, and the radius of the Earth is 6.38 × 106 m.)

Accepted Answer

A)  9.55 N/kg. 
B)  8.43 N/kg. 
C)  3.08 N/kg. 
D)  6.33 N/kg. 
E)  5.28 N/kg. 
A)  9.55 N/kg. 
B)  8.43 N/kg. 
C)  3.08 N/kg. 
D)  6.33 N/kg. 
E)  5.28 N/kg.

Question 12

The fundamental force that governs the motion of the planets is the

Accepted Answer

A)  strong force. 
B)  weak force. 
C)  electromagnetic force. 
D)  gravitational force. 
A)  strong force. 
B)  weak force. 
C)  electromagnetic force. 
D)  gravitational force.

Question 13

Which would require the least force to move a box along a floor with a coefficient of friction of 0.30?

Accepted Answer

A)  pull it with a rope at an angle of 30° above the horizontal 
B)  push it at an angle of 30° below the horizontal 
C)  either pull it with a rope at an angle of 30° above the horizontal or push it at an angle of 30° below the horizontal 
D)  not enough information to solve 
A)  pull it with a rope at an angle of 30° above the horizontal 
B)  push it at an angle of 30° below the horizontal 
C)  either pull it with a rope at an angle of 30° above the horizontal or push it at an angle of 30° below the horizontal 
D)  not enough information to solve

Question 14

The fundamental force that has the shortest range is the

Accepted Answer

A)  strong force. 
B)  weak force. 
C)  electromagnetic force. 
D)  gravitational force. 
A)  strong force. 
B)  weak force. 
C)  electromagnetic force. 
D)  gravitational force.

Question 15

What is the gravitational force between two nuclei, each of mass 3.20 × 10-27 kg, which are separated by a distance of 1.06 × 10-10 m? (G = 6.67 × 10-11 N m2/kg2)

Accepted Answer

A)  6.08 × 10-45 N 
B)  6.08 × 10-44 N 
C)  6.08 × 10-43 N 
D)  6.08 × 10-42 N 
A)  6.08 × 10-45 N 
B)  6.08 × 10-44 N 
C)  6.08 × 10-43 N 
D)  6.08 × 10-42 N

Question 16

The force that causes an object to fall to Earth is the

Accepted Answer

A)  gravitational force. 
B)  electromagnetic force. 
C)  weak interaction. 
D)  strong nuclear force. 
A)  gravitational force. 
B)  electromagnetic force. 
C)  weak interaction. 
D)  strong nuclear force.

Question 17

In order to slide a 753 N box across the floor at a constant speed, you must push horizontally with a force of magnitude 452 N. What is the coefficient of kinetic friction?

Accepted Answer

A)  1.66 
B)  0.600 
C)  0.660 
D)  0.580 
E)  1.65 
A)  1.66 
B)  0.600 
C)  0.660 
D)  0.580 
E)  1.65

Question 18

In order to slide a 70 kg box across the floor at a constant speed, you must push horizontally with a force of magnitude 351 N. What is the coefficient of kinetic friction?

Accepted Answer

A)  0.15 
B)  0.58 
C)  0.34 
D)  0.51 
E)  0.68 
A)  0.15 
B)  0.58 
C)  0.34 
D)  0.51 
E)  0.68

Question 19

A force of magnitude 451 N is applied horizontally to 111 kg box, which is at rest on the floor. The coefficient of static friction between the box and the floor is 0.450. What is the magnitude of the force of friction from the floor on the box?

Accepted Answer

A)  490 N 
B)  0.00 N 
C)  108 N 
D)  451 N 
E)  203 N 
A)  490 N 
B)  0.00 N 
C)  108 N 
D)  451 N 
E)  203 N

Question 20

A large massive rock is in contact with the Earth. Draw a force diagram for the rock and the Earth. Which of the following statements is true?

Accepted Answer

A)  The gravitational force on the rock due to the Earth and the gravitational force on the Earth due to the rock are interaction partners. 
B)  The gravitational force on the rock due to the Earth and the contact force on the Earth due to the rock are interaction partners. 
C)  The contact force on the Earth due to the rock and the gravitational force on the Earth due to the rock are interaction partners. 
D)  The gravitational force on the Earth due to the rock and the contact force on the Earth due to the rock are interaction partners. 
A)  The gravitational force on the rock due to the Earth and the gravitational force on the Earth due to the rock are interaction partners. 
B)  The gravitational force on the rock due to the Earth and the contact force on the Earth due to the rock are interaction partners. 
C)  The contact force on the Earth due to the rock and the gravitational force on the Earth due to the rock are interaction partners. 
D)  The gravitational force on the Earth due to the rock and the contact force on the Earth due to the rock are interaction partners.

Exam 4: Force and Newtons Laws of Motion

The net force on a moving object suddenly becomes zero. The object then

A 1.7 kg model airplane is flying north at 12.5 m/s initially, and 25 seconds later is observed heading 30 degrees west of north at 25 m/s. What is the magnitude of the average net force on the airplane during this time interval?

A box is pushed across a horizontal table at a constant speed. Of the forces acting, which pair do we know are equal in magnitude because of Newton's third law?

A tractor of mass M1 = 2,000 kg is pulling a trailer of mass M2 = 5,000 kg. If the tractor-trailer is accelerated at 2.0 m/s2, and air resistance is negligible, then the magnitude of the force the tractor applies to the road is

When an object is in translational equilibrium, which of these statements is not true?

An 80.0 kg person is riding in an elevator that is accelerating at 2.40 m/s2 downward. The apparent weight of the 80.0 kg person measured on a scale in the elevator is

Within a given system, the internal forces

The gravitational field at the Earth due to the Moon is about (G = 6.67 × 10-11 N m2/kg2, the mass of the Moon is 7.35 × 1022 kg, and the distance to the Moon is 3.85 × 108 m)

What is the gravitational field strength at the location of a satellite that is orbiting the Earth at an altitude of 5,000 km? (G = 6.67 × 10-11 N m2/kg2, the mass of the Earth is 5.98 × 1024 kg, and the radius of the Earth is 6.38 × 106 m.)

The fundamental force that governs the motion of the planets is the

Which would require the least force to move a box along a floor with a coefficient of friction of 0.30?

The fundamental force that has the shortest range is the

What is the gravitational force between two nuclei, each of mass 3.20 × 10-27 kg, which are separated by a distance of 1.06 × 10-10 m? (G = 6.67 × 10-11 N m2/kg2)

The force that causes an object to fall to Earth is the

In order to slide a 753 N box across the floor at a constant speed, you must push horizontally with a force of magnitude 452 N. What is the coefficient of kinetic friction?

In order to slide a 70 kg box across the floor at a constant speed, you must push horizontally with a force of magnitude 351 N. What is the coefficient of kinetic friction?

A force of magnitude 451 N is applied horizontally to 111 kg box, which is at rest on the floor. The coefficient of static friction between the box and the floor is 0.450. What is the magnitude of the force of friction from the floor on the box?

A large massive rock is in contact with the Earth. Draw a force diagram for the rock and the Earth. Which of the following statements is true?

Introduction

Motion Along a Line

Motion in a Plane

Circular Motion

Conservation of Energy

Linear Momentum

Torque and Angular Momentum

Fluids

Elasticity and Oscillations

Waves

Sound

Temperature and the Ideal Gas

Heat

Thermodynamics

Electric Forces and Fields

Electric Potential

Electric Current and Circuits

Magnetic Forces and Fields

Electromagnetic Induction

Alternating Current

Electromagnetic Waves

Reflection and Refraction of Light

Optical Instruments

Interference and Diffraction

Relativity

Early Quantum Physics and the Photon

Quantum Physics

Nuclear Physics

Particle Physics

Filters

A tractor of mass M₁ = 2,000 kg is pulling a trailer of mass M₂ = 5,000 kg. If the tractor-trailer is accelerated at 2.0 m/s², and air resistance is negligible, then the magnitude of the force the tractor applies to the road is

An 80.0 kg person is riding in an elevator that is accelerating at 2.40 m/s² downward. The apparent weight of the 80.0 kg person measured on a scale in the elevator is

The gravitational field at the Earth due to the Moon is about (G = 6.67 × 10^-11 N m²/kg², the mass of the Moon is 7.35 × 10²² kg, and the distance to the Moon is 3.85 × 10⁸ m)

What is the gravitational field strength at the location of a satellite that is orbiting the Earth at an altitude of 5,000 km? (G = 6.67 × 10^-11 N m²/kg², the mass of the Earth is 5.98 × 10²⁴ kg, and the radius of the Earth is 6.38 × 10⁶ m.)

What is the gravitational force between two nuclei, each of mass 3.20 × 10^-27 kg, which are separated by a distance of 1.06 × 10^-10 m? (G = 6.67 × 10^-11 N m²/kg²)