Question

Alana summarized what happens when a ball sitting on top of a grassy hill rolls down the hill.

The motionless ball has potential energy. Once the ball starts to roll down the hill, new kinetic energy is made. As the ball rolls across the grass, it slows down. The kinetic energy of the ball is converted to other forms of energy.

Which best describes Alana’s error?

The motionless ball does not have energy because it is still.
Kinetic energy is not made; it is a result of energy transformation.
The ball cannot slow down unless someone touches it.
The energy is not converted; it disappears.

Answer 1

"Kinetic energy is not made; it is a result of energy transformation."

Explanation: The ball's gravitational potential energy is converted into kinetic energy as it rolls down the hill — energy is transformed, not created. When it slows on the grass, that kinetic energy is converted into other forms (mostly thermal and sound) by friction.