Physics: Forces

When an object is moving, friction acts in the _______ direction as the motion.

• perpendicular

• same

• opposite

• precise

Friction is a contact force that acts _______ to the surfaces in contact.

• parallel

• perpendicular

• equal

• at an acute angle

The type of friction that prevents an object from moving is called _______ friction.

• rolling

• fluid

• kinetic

• static

A type of friction that occurs when air pushes against a moving object it to decelerate.

• surface area

• air resistance

• velocity

• gravity

What affect would decreasing the normal force between two objects have on the force of friction?

• The force of friction would increase.

• The force of friction would decrease.

• The force of friction would remain the same.

• The force of friction would disappear completely.

A person not paying attention while skateboarding hits a rock. The skateboard stops...they don't.

• The Law of Inertia (1st law)
• The Law of Acceleration (2nd law)
• The Law of Conservation of Momentum
• Action Reaction Law (3rd law)

Letting go of a balloon full of air is demonstrating Newton's ______ _______ ________ _________ because the air comes out of the back and the balloon moves forward.

• 1st law of motion

• 2nd law of motion

• 3rd law of motion

• 13th law of motion

What is Newton's First Law

• F=ma
• Every action has an equal and opposite reaction
• An object at rest stays at rest, an object in motion stays in motion. 
• Friction 

The combination of all the forces acting on an object is the...

• net force
• action force
• reaction force
• balance force

Name the missing force....

• weight force
• normal force
• frictional force
• tension force