A1-kg car and a 2-kg car are both released from the top of the same hill and roll down a frictionless track. at the bottom of the hill, which car will have the greater speed? which car will have the greater kinetic energy?

Suppose that a comet that was seen in 563 a.d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

The energy equivalent of the rest mass of an electron is

How can waves travel through ground?