Explain how motion is relative

Relative motion is the calculation of the motion of an object with regard to some other moving or stationary object. Thus, the motion is not calculated with reference to the earth, but is the velocity of the object in reference to the other moving object as if it were in a static state.

answer: point c: b. 1/2 potential, 1/2 kinetic, point a: 3/4 of its potential energy, point d or b: 3/4 potential, 1/4 kinetic

explanation: i cant explain. it's difficult to explain.

d. platinum would have the greatest temperature increase because it has the lowest specific heat.