What is the name of this insect and what is it's charteristics

The a metal retainer that keeps the rolling elements evenly spaced. n a. seal n b. separator n c. bearing n d outer race

To do work, this truck uses energy stored in chemical fuel and an electrical battery. how much total energy does this truck put out?

Explain how the energy of rubber ball is tranforned as it roll down a ramp. give evidence that the energy of the og the ball remains the same at all points on the ramp