Question

A research satellite of mass $200kg$ circles the earth in an orbit of average radius $\frac{3R}{2},$ where R is the radius of the earth. Assuming the gravitational pull on a mass $1kg$ on earth's surface to be $10N$, the pull on this satellite will be:

• A. $860N$
• B. $889N$
• C. $827N$
• D. $798N$

Answer 1

Answer: (B)

$889N$

$F=$ Pull on satellite at height $h=mg\left(\frac{R}{R+h}\right)$
But, $h=\frac{R}{2}$
$\Rightarrow F=200\times 10\times {\left(\frac{2R}{3R}\right)}^2$$=889N$