Question

Newton’s first law of motion was a giant leap forward in scientific thought during Newton’s time. Even today, the idea is sometimes difficult at first for people to understand.

Which statement is the best example of an object and motion that would make it hard for people to accept Newton’s first law?

A rolling ball eventually slows down and comes to a stop.
A wagon must be pushed before it begins to move.
The heavier the load in a cart, the harder the cart is to turn.
A box does not move when pushed equally from opposite sides.

Answer 1

A. A rolling ball eventually slows down and comes to a stop.

Explanation: Newton's first law says an object in motion will keep moving at constant velocity unless a net external force acts on it. Seeing a rolling ball slow and stop suggests (incorrectly) that motion requires a continued push, so it makes the idea of inertia hard to accept. In reality friction and air resistance provide the net force that slows the ball.