Alicia gives her brother a push while he is seated on a swing. She finds that after a few seconds, she needs to push again to keep him going. The reason her brother slows down is because the mechanical energy is converted into
A: thermal energy that is released into the atmosphere.

The wheels and gears of a machine are greased in order to decrease
A: friction

Carlos puts a new battery into a radio. What does the battery supply to the radio that makes it turn on?
A: electricity

Which BEST explains why green marine algae are most often restricted to the top 100 meters of the ocean?
A:
They can live only where there is light.