Question

If the angular momentum of a satellite of mass $400\, kg$ moving around the earth in radius $4 \times 10^{7}\, m$ is $y \times 10^{12} \, kg\, m ^{2}\, s ^{-1}$, then find $y$.
(Answer should be perfect integer)

Answer 1

Angular momentum
$=m v r$.
$=m \sqrt{\frac{G M}{r}} r$
$=400 \times \sqrt{\frac{6.6 \times 10^{-11} \times 6 \times 10^{24}}{4 \times 10^{7}}} \times 4 \times 10^{7}$
$=3.14 \times 10^{3} \times 16 \times 10^{9}$
$=50.24 \times 10^{12}\, kg\, m ^{2}\, s ^{-1}$