Question

Carole is surprised when she makes an emergency stop and the tissue box that had been in the back window of her car hits the back of her seat. How would Newton explain what happened?
A) An object in motion tends to stay in motion.
B) The force of stopping caused it to accelerate.
Eliminate
C) Box mass and inertia accelerate with the force.
D) Every action has an equal and opposite reaction.

Answer 1

A.) An object in motion tends to stay in motion

Answer 2

Answer:

A) An object in motion tends to stay in motion.

Explanation:

Newton's first law (also known as Law of Inertia) states that:

"when an object at rest is acted upon balanced forces, it tends to stay at rest, while when an object in motion is acted upon balanced forces, it tends to stay in motion with constant velocity"

If we apply this law to this situation, we see that:

- The tissue box is initially in motion together with the car

- When Carole makes the emergency stop, the car stops. However, the tissue box is not tied to the car: it means that there are no forces that keeps the box in its original place

- Therefore, according to Newton's first law, the box tends to stay in motion. And so, it continues moving forward, until it hits the back of Carole's seat.