e) A escalator carries 60 people of average mass 70kg to a height of 5m in one minute. Find the power needed to do this? 4

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.

Why is the use of carbon-14 limited

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?