The energy of a 50 kg student about to jump off a 1 meter counter
im confused what this means

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

The earth remains in orbit around the sun due to the force of gravity. how does the force of gravity exerted by the sun on the earth compare to the force of gravity exerted by the earth on the sun?

Power can be defined as a. the distance over which work was done. b. how much work can be done in a given time. c. all the work in an given area. d. the energy required to do work.