A 75.0 kg man pushes on a 500,000 kg wall for 250 s but it does not move. a. How much work does he do on the wall?
b. How much energy is used?
c. How much power is exerted?

Aparticle travels in a circular orbit of radius 21 m. its speed is changing at a rate of 23.1 m/s2 at an instant when its speed is 37.2 m/s. what is the magnitude of the acceleration (in m/s? ) of the particle?

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Ways that industry and agriculture use physical properties to separate substances