Q. Weight of $1kg$ becomes 1/6 on moon. If radius of moon is $1.768 \times 10^{6}\ m$, then the mass of moon will be
A) $1.99 \times 10^{30}kg$
B) $7.56 \times 10^{22}kg$
C) $5.98 \times 10^{24}kg$
D) $7.65 \times 10^{22}kg$
Explanation
(d) $g_{m} = \frac{GM_{m}}{R_{m}^{2}}$ and $g_{m} = \frac{g_{e}}{6} = \frac{9.8}{6}m/s^{2} = 1.63\ m/s^{2}$
Substituting $R_{m} = 1.768 \times 10^{6}m,\ g_{m} = 1.63\ m/s^{2}$
and $G = 6.67 \times 10^{- 11}N$-$m^{2}/kg^{2}$ We get
$M_{m} = 7.65 \times 10^{22}kg$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.