Newton's Laws of Motion

According to the passage, who was the Italian astronomer that suggested once an object is in motion no force is needed to keep it moving?

• Galileo Galilei

• Isaac Newton

• Johannes Kepler

• Nicolaus Copernicus

What does the first law of motion state about an object at rest and an object in motion?

• An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force.

• An object at rest will always start moving on its own.

• An object in motion will eventually stop without any force.

• An object at rest and in motion will both change direction automatically.

What is inertia?

• Inertia is an object's resistance to change in motion.

• Inertia is the force that moves objects.

• Inertia is the energy stored in an object.

• Inertia is the speed of an object.

According to the first law of motion, an object’s velocity will change even if no unbalanced net force is applied.

• True

• False

Which of the following objects would have more inertia: a car or a ping pong ball?

• A car

• A ping pong ball

Why does stopping a car require more force than stopping a ping pong ball, according to the passage?

• Because the car has more mass, more inertia, and thus it is harder to change its motion.

• Because the car is smaller and lighter than a ping pong ball.

• Because the car moves slower than a ping pong ball.

• Because the car is made of rubber and bounces more easily.

Refer to the diagram of Newton's First Law of Motion. What will happen to an object at rest if no unbalanced force acts on it?

• It will start moving

• It will remain at rest

• It will change direction

• It will speed up

According to Newton's Second Law of Motion, what two factors does acceleration depend on?

• An object's mass and the strength of the force acting on it.

• An object's volume and its color.

• The temperature and the object's shape.

• The object's speed and its direction.

What is the formula for momentum as described in the passage?

• Momentum = mass x velocity (speed)

• Momentum = mass + velocity (speed)

• Momentum = mass / velocity (speed)

• Momentum = velocity (speed) / mass

Suppose you are riding your bike and you offer your friend a ride. Why does it require more force to accelerate the bike with your friend on it compared to when you are riding alone?

• Because the total mass increases, requiring more force to achieve the same acceleration.

• Because the bike becomes less stable with two people.

• Because the tires have more friction with the road.

• Because the air resistance doubles with two people.