A rocket is fired vertically with a speed of 5 km `s^(-1)` from the earth’s surface. How far from the earth does the rocket go before returning to the earth ? Mass of the earth = `6.0 × 10^(24)` kg; mean radius of the earth = `6.4 × 10^6`m; G = `6.67 × 10^(–11)` N `m^2` `kg^(–2)`.