# What is the change in the rocket’s kinetic energy? Does the kinetic energy increase or decrease?

A rocket with mass 5.00×103kg is in a circular orbit of radius 7.20×106m around the earth. The rocket’s engines fire for a period of time to increase that radius to 8.80 \times 10^{6} \mathrm{m, with the orbit again circular.

a) What is the change in the rocket’s kinetic energy?
Does the kinetic energy increase or decrease?
b) What is the change in the rocket’s gravitational potential energy?
Does the potential energy increase or decrease?
c) How much work is done by the rocket engines in changing the orbital radius?