A meteoroid starts from rest at a distance from Earth’s centre and falls directly…

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

Problem

A meteoroid starts from rest at a distance

10R_{\oplus}

from Earth’s centre and falls directly toward Earth. Neglecting atmospheric drag, determine its speed when it reaches

2R_{\oplus}

. (Take

g = 9.8\,\text{m s}^{-2}

and

R_{\oplus}=6.4\times10^{6}\,\text{m}

.) (a)

10\,\text{km s}^{-1}

(b)

5.0\,\text{km s}^{-1}

(c)

7.1\,\text{km s}^{-1}

(d)

8.7\,\text{km s}^{-1}