Ignoring air resistance

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Ignoring air resistance, how much work does the gravitational force do on a

1\,\text{kg}

object that falls from a height of

1000\,\text{km}

above Earth’s surface to the surface? (Take

R_{\oplus}=6400\,\text{km}

and

G M_{\oplus}=6.4\times10^{14}\,\text{m}^{3}\,\text{s}^{-2}

.) (a)

15.6\,\text{MJ}

(b)

-13\,\text{MJ}

(c)

13\,\text{MJ}

(d)

9.8\,\text{MJ}