What happens to gravitational potential energy as a roller coaster moves down a hill?
it remains constant.
it increases.
it is converted to kinetic energy.
it is converted to elastic potential energy.

What happens to light waves from a star as the star moves away from earth?

Describe the function of the endomembrane system? what organelles are involved?

You are your friend move a new refrigerator into his kitchen. you apply a horizontal force of 252 n in the negative x direction to try and move the 56 kg refrigerator. the coefficient of static friction is 0.61. (a) how much static frictional force does the floor exert on the refrigerator? give both magnitude (in n) and direction. magnitude n direction (b) what maximum force (in n) do you need to apply before the refrigerator starts to move?