Show that the weight of an object on the moon is one-sixth of its weight on the earth. [Given: mass of earth $= 5.98 \times 10^{24} \ kg$,mass of moon $= 7.36 \times 10^{22} \ kg$,radius of earth $= 6.37 \times 10^{6} \ m$,radius of moon $= 1.74 \times 10^{6} \ m$]

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Let the mass of an object be $m$. Let its weight on the moon be $W_{m}$ and its weight on the earth be $W_{E}$.
Using the universal law of gravitation,the weight of an object on the moon is given by $W_{m} = \frac{GM_{m}m}{R_{m}^{2}}$,where $M_{m}$ is the mass of the moon and $R_{m}$ is its radius.
Similarly,the weight of the object on the earth is $W_{E} = \frac{GM_{E}m}{R_{E}^{2}}$,where $M_{E}$ is the mass of the earth and $R_{E}$ is its radius.
Taking the ratio of the two weights:
$\frac{W_{m}}{W_{E}} = \frac{GM_{m}m}{R_{m}^{2}} \times \frac{R_{E}^{2}}{GM_{E}m} = \frac{M_{m}}{M_{E}} \times \left( \frac{R_{E}}{R_{m}} \right)^{2}$
Substituting the given values:
$\frac{W_{m}}{W_{E}} = \frac{7.36 \times 10^{22}}{5.98 \times 10^{24}} \times \left( \frac{6.37 \times 10^{6}}{1.74 \times 10^{6}} \right)^{2}$
$\frac{W_{m}}{W_{E}} \approx 0.0123 \times (3.66)^{2} \approx 0.0123 \times 13.4 = 0.165 \approx \frac{1}{6}$
Thus,the weight of an object on the moon is one-sixth of its weight on the earth.

Explore More

Similar Questions

Why does a body weigh more at the poles than at the equator?

The weight of an object:

Amit buys a few grams of gold at the poles as per the instruction of one of his friends. He hands over the same when he meets him at the equator. Will the friend agree with the weight of gold bought? If not,why? [Hint: The value of $g$ is greater at the poles than at the equator.]

State whether the following statement is True or False:
The centre of mass and centre of gravity for a small body lie at the same point.

$A$ man weighs $600\, N$ on the surface of the Earth. What would be his mass and weight on the surface of the Moon? $(g = 10\, m s^{-2})$

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo