8th Unit One Lesson Three Quiz

What is a force?

• a form of potential energy

• a push or pull on an object

• an electrical or magnetic field

• an object that is moving or changing shape

Which of these is considered a contact force?

• the force between two magnets

• the gravitational pull of a planet

• the friction between an object and air

• the force between two charged particles

A box has two forces acting on it. One force is 100N upward. Another force is 50N downward. What is the net force on the box?

• 50 N upward

• 150 N upward

• 50 N downward

• 150 N downward

Melanie watched the path of a baseball followed after a pitcher threw it. She noticed that the ball traveled horizontally away from the pitcher as well as downward toward the ground. What force caused the ball to accelerate in the downward direction when it was thrown?

• applied force

• air resistance

• electrical force

• gravitational force

Why are some forces considered to be noncontact forces?

• Objects must be far apart in order to exert a force.

• Objects do not have to touch each other to experience a force.

• Objects push each other apart to increase the distance between them.

• Objects must be large in size in order to exert a force that is strong enough to notice.

A vase sits motionless on a table. Which statement describes the forces acting on the vase?

• There are no forces acting on the vase.

• The unbalanced force of gravity is acting on the vase.

• The force of gravity is balanced by the force from the table.

• The force of the table on the vase is slightly greater than the force of gravity on the vase.

Which statement best describes the relationship between velocity and acceleration?

• Velocity is the rate of change in acceleration.

• Acceleration is the rate of change in velocity.

• Velocity and acceleration are not related to each other.

• Acceleration can only be a positive value regardless of the velocity.