If a bike rider uses chemical energy to push the pedals and that transforms into
mechanical energy, what happens to the
thermal energy generated by the body
from pedalling the bicycle (the bicyclist
gets hot)?

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

The average density of the planet uranus is 1.27 103 kg/m3. the ratio of the mass of neptune to that of uranus is 1.19. the ratio of the radius of neptune to that of uranus is 0.969. find the average density of neptune.

What practical value did astronomy offer to ancient civilizations?