Question

A body is projected vertically upward from the surface of the earth with escape velocity. The time in which it attains a height 8r is

Answer 1

Answer:

In common usage, the initial point is on the surface of a planet or moon. On the surface of the Earth, the escape velocity is about 11.2 km/s, which is approximately 33 times the speed of sound (Mach 33) and several times the muzzle velocity of a rifle bullet (up to 1.7 km/s).