a person skateboarding is part of a closed system that has 1450 j of mechanica energy if the kinetic energy of the person i. creases from 200 J to 825 J what happens to the gravitational potential energy of the system

Avery hard rubber ball (m = 0.5 kg) is falling vertically at 4 m/s just before it bounces on the floor. the ball rebounds back at essentially the same speed. if the collision with the floor lasts 0.05 s, what is the average force exerted by the floor on the ball?

What type of light does this light bulb produce most (i. e. at what wavelength does the spectrum have maximum intensity)?

Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.