8th grade- Chapter 2 Motion

You push on a book and it moves. This is a _______________ force.

• action-reaction

• unbalanced

• balanced

• inertia

Two busses collide that have the same mass and speed. After the collision, the momentum of the busses is

• twice the original momentum

• half the original momentum

• the same as the original momentum

• there is no momentum after the crash

______________ friction keeps you in your seat when a car goes around a corner.

• Sliding

• Static

• Fluid

Which of the following is the equation for momentum?

• p = m / v

• p = v / m

• p = m x v

• p = f / m

If the force of an object is 20 N and the mass is 4 kg, what is the acceleration of the object?

• 80 m/s/s

• 16 m/s/s

• 5 m/s/s

• 24 m/s/s

The upward force on a ball falling through the air is called

• inertia

• gravity

• terminal velocity

• air resistance

______________ is the tendency of an object to resist a change in motion.

• gravity

• inertia

• balanced forces

• air resistance

Water pushes you forward when you push against it. This is an example of Newton's ______ Law.

• 1st

• 2nd

• 3rd

When objects stick together after a collision, the collision is said to be

• elastic

• inelastic

• momentum negative

Which of the following is a way to reduce friction?

• make surface rougher

• add mass to object

• add lubricants

• push down harder