Stemscopes Exam STEMscopes Forces and Motion 3

Question 1

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

Accepted Answer

A person pushing a shopping cart

Answer

Gravity pulling a book down

Answer

A magnet attracting a paper clip from a distance

Answer

Earth pulling the Moon into orbit

Question 2

If the mass of an object doubles while the net force on it stays the same, its acceleration will:

Accepted Answer

Decrease by half

Answer

Double

Answer

Stay the same

Answer

Increase by four times

Question 3

A weight hangs from a spring scale showing 30 N. This 30 N represents the object's:

Accepted Answer

Weight (gravitational force)

Answer

Mass

Answer

Inertia

Answer

Friction force

Question 4

When a rubber ball bounces off a floor, the floor exerts a force on the ball. According to Newton's Third Law, the ball must:

Accepted Answer

Exert an equal and opposite force on the floor

Answer

Exert no force on the floor since it is lighter

Answer

Exert a greater force on the floor due to impact

Answer

Only experience the floor's force, not exert one

Question 5

A student measures the time it takes a toy car to travel 2 meters: it takes 4 seconds. What is the car's average speed?

Accepted Answer

0.5 m/s

Answer

0.25 m/s

Answer

2 m/s

Answer

8 m/s

Question 6

Which statement best describes inertia?

Accepted Answer

The tendency of an object to resist changes in its state of motion

Answer

A force that pulls objects toward Earth

Answer

The acceleration of an object due to gravity

Answer

The force needed to stop a moving object

Question 7

Two teams in a tug-of-war pull on a rope with equal and opposite forces. The rope does not move. This is because the forces are:

Accepted Answer

Balanced with a net force of zero

Answer

Unbalanced with a net force to the left

Answer

Unbalanced with a net force to the right

Answer

Action-reaction pairs on the same object