A weightlifter pulls on a 225 kg bar with 1600 N of force, but the bar does not move. How much work is performed?

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

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?

3. a lunar exploration vehicle was created by a research team. it weighs 3,000 kg on the earth. it needs an acceleration of 10 m/s2 on the moon. in order to have the same acceleration, what will be the net force acting on the vehicle on the earth?