# Math Help - Finding the intial velocity of a spacecraft

1. ## Finding the intial velocity of a spacecraft

Estimate the initial velocity in meters/s that needs to be given to a spacecraft moving straight away from earth to make it reach the lunar orbit at 383000 km away from the centre of the earth.

The initial height of the spacecraft is H km above the surface of the earth. The radius of the earth is 6370 km.

H[km] = 4420;

2. Originally Posted by m_i_k_o
Estimate the initial velocity in meters/s that needs to be given to a spacecraft moving straight away from earth to make it reach the lunar orbit at 383000 km away from the centre of the earth.

The initial height of the spacecraft is H km above the surface of the earth. The radius of the earth is 6370 km.

H[km] = 4420;
use energy principles.