Identifying Newton's Laws

Which law states that an object that experiences a net force will accelerate in the direction of the net force?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

This is the 2nd law.

Tags

NGSS.HS-PS2-1

Which law states that an object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an unbalanced force?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

This is the 1st law.

Which law states that for every action there is an equal and opposite reaction?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

This is the 3rd law.

In which law is the net force on an object equal to zero? (i.e. in which law is an object at equilibrium?)

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 1st law applies because the system is at rest, so it is in equilibrium and forces are balanced.

A lamp sits on a table.

Which of Newton's Law does this best demonstrate?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 1st law applies because the system is at rest, so it is in equilibrium and forces are balanced.

You kick a door and your foot hurts.

Which of Newton's Law does this best demonstrate?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 3rd law applies because you are exerting a force on the door when you kick it, and the door is exerting and equal and opposite force on you - so the door is also kicking you!

A penny is dropped from the empire state building (not yet at terminal velocity).

Which of Newton's Law does this best demonstrate?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 2nd law applies because the penny is in freefall, so it is accelerating - there is a net force due to gravity.

Tags

NGSS.HS-PS2-1

A penny is dropped from the empire state building and reaches terminal velocity

(falling at a constant rate)

Which of Newton's Law does this best demonstrate?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 1st law applies because the penny is falling at a constant velocity (it is NOT accelerating), so forces are balanced and it is in equilibrium

You slam on the brakes, slowing your car to a stop.

Which of Newton's Law does this best demonstrate?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 2nd law applies because the force of the brakes is causing the car to accelerate/slow down.

You slam on the brakes, slowing your car, but your body continues forward.

Which of Newton's Law does this best demonstrate?

• 1st Law

• 2nd Law

• 3rd Law

Answer explanation

The 1st law applies because without a net force, your body wants to stay in motion.