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

A contact force requires physical contact between objects; a person pushing a cart is a direct contact force called an applied force.

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

From Newton's Second Law (a = F/m), if mass doubles and force stays constant, acceleration is halved.

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

Weight is the gravitational force on an object measured in Newtons; a spring scale measures this force directly.

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

Newton's Third Law requires action-reaction pairs: the ball exerts an equal and opposite force on the floor at the same time the floor pushes the ball upward.

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

Average speed = distance ÷ time = 2 m ÷ 4 s = 0.5 m/s.

Stemscopes Exam Practice Test

Stemscopes Exam Practice Test

Stemscopes Exam STEMscopes Forces and Motion 3