A space probe is initially in a circular orbit of radius around the Earth

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

1000\,\text{kg}

space probe is initially in a circular orbit of radius

1.0\times10^{7}\,\text{m}

around the Earth. Its engine is switched off and the probe is allowed to fall freely to a new circular orbit of radius

4.0\times10^{6}\,\text{m}

(assume no atmosphere). Find the amount of mechanical energy released during this orbital transfer.