Im bored help me join this if u want with friends

Abicycle slows down when the rider applies the brakes. what type of energy transformation is involved in this example? a. kinetic energy into heat energy b. heat energy into potential energy c. potential energy into kinetic energy d. kinetic energy into mechanical energy

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.

What would be the radius of the earth if it had its actual mass but had the density of nuclei? express your answer to two significant figures and include the appropriate units.