Forces Review

Recall the best definition for air resistance.

• A force that opposes the motion of an object in the air

• A force that provides thrust

• An electrical property of air that impedes the motion of an object

Two soccer players happen to kick the ball at the exact same time. The diagram below shows the forces they apply to the ball. Assume that the players apply the same sized force to the ball.

State how you would calculate the net force acting on the ball.

• Add the forces together

• Subtract the forces

Name this scientific instrument.

• Newtons cradle

• Force meter

• Newtons hook

• Mini scale

Friction that acts on objects that are moving

• Static friction

• Kinetic friction

Identify which direction the force is being applied by the girl below.

• To the left

• To the right

Identify in which of these situations friction is considered helpful.

• In an engine with moving parts

• Using the breaks on your bike

• Long distance plane travel

• Writing with a pencil

Consider the following scenario, then identify if friction is helpful or harmful.

A snowboarder trying to slow down as he traverses a mountain

• Helpful

• Harmful

"A push or pull applied by one object to another object, causing a change in motion or shape."

• Balanced force

• Unbalanced force

• Friction

• Gravity

The amount of friction is dependent upon the ________ of the surface

• Gravity

• Forces

• Roughness

"A force which is only applied when one object is touching the other."

• Contact force

• Non-Contact force

• Balanced force

• Unbalanced force