Understanding Forces and Motion

Which of the following best defines a force?

• An object's total mass.

• A push or a pull that results from an interaction with an agent.

• The acceleration of an object over time.

• The rate at which work is done.

A free body diagram of a book resting on a table is drawn. Which force is best represented as acting perpendicular to the supporting surface?

• Applied force.

• Force of gravity.

• Frictional force.

• Normal force.

An object is accelerating to the right. What can you conclude about the net force acting on the object?

• The net force is zero.

• The net force is in the opposite direction of the acceleration.

• The net force is in the same direction as the acceleration.

• The net force is applied by a contact agent only.

Two forces, one of 15 N to the right and another of 5 N to the left, act on an object. What is the net force on the object?

• 20 N to the right.

• 10 N to the right.

• 10 N to the left.

• 20 N to the left.

According to Newton's Second Law of Motion, what effect does a net force applied to an object have?

• It causes the object to increase in density.

• It causes the object to accelerate.

• It causes the object to move at a constant velocity.

• It causes the object to decrease in mass.

A force-acceleration graph is plotted for a series of experiments on a single object. What does the slope of this graph represent?

• The acceleration of the object.

• The net force applied to the object.

• The mass of the object.

• The velocity of the object.

An object with a mass of 5 kg is pushed with a net force of 20 N. According to Newton's Second Law, what is the acceleration of the object?

• 100 m/s2

• 4 m/s2

• 0.25 m/s2

• 15 m/s2

How is the acceleration of an object related to the force applied and the mass of the object?

• Directly proportional to force and directly proportional to mass.

• Inversely proportional to force and directly proportional to mass.

• Directly proportional to force and inversely proportional to mass.

• Inversely proportional to force and inversely proportional to mass.

A system is defined as the object being analyzed, and the external world is everything outside of the system. In a free body diagram, where are the forces from the external world shown?

• Acting within the system.

• Not shown at all.

• Acting on the dot representing the object.

• Acting on the external world, not the system.