Question

A rocket is set to blast from the surface of Earth. What speed will it need to achieve in order to stay in orbit around the Earth at an altitude of 300 km? Note distance here to the center of the Earth is 6.7*10^6 km and the mass of Earth is 6*10^24.

Answer 1

For example, a spacecraft leaving the surface of Earth needs to be going 7 miles per second, or nearly 25,000 miles per hour to leave without falling back to the surface or falling into orbit.