Pre-test: Forces and Newton's Laws

Which of the following is an example of a contact force?

• Gravity

• Friction

• Magnetic force

• Electric force

What type of force is gravity?

• Contact force

• Non-contact force

• Balanced force

• Unbalanced force

When the net force on an object is zero, the forces are said to be:

• Unbalanced

• Balanced

• Non-contact

• Acting at a distance

An object remains at rest or continues to move at a constant velocity unless acted upon by an external force. This statement describes:

• Newton's First Law

• Newton's Second Law

• Newton's Third Law

• The law of universal gravitation

• Newton's First Law

• Newton's Second Law

• Newton's Third Law

• The law of universal gravitation

For every action, there is an equal and opposite reaction. This statement summarizes:

• Newton's First Law

• Newton's Second Law

• Newton's Third Law

• The principle of conservation of momentum

Which of the following scenarios best illustrates unbalanced forces?

• A book resting on a table

• A car moving at a constant speed

• A ball rolling to a stop

• A satellite orbiting Earth in a stable orbit

What happens to the acceleration of an object if the net force acting on it doubles?

• It remains the same

• It halves

• It doubles

• It quadruples

Which of the following is NOT a non-contact force?

• Magnetic force

• Gravitational force

• Friction

• Electric force

If the mass of an object is constant, and the force applied to it increases, what happens to the acceleration?

• It remains constant

• It decreases

• It increases

• It becomes zero