- Home
- Standard 11
- Physics
7.Gravitation
medium
The mass of the moon is $\frac{1}{{81}}$ of the earth but the gravitational pull is $\frac{1}{6}$ of the earth. It is due to the fact that
A
The radius of the moon is $\frac{{81}}{6}$ of the earth
B
The radius of the earth is $\frac{9}{{\sqrt 6 }}$ of the moon
C
Moon is the satellite of the earth
D
None of the above
Solution
(b) Gravitational pull depends upon the acceleration due to gravity on that planet.
${M_m} = \frac{1}{{81}}{M_e}$,${g_m} = \frac{1}{6}{g_e}$
$g = \frac{{GM}}{{{R^2}}}$==>$\frac{{{R_e}}}{{{R_m}}} = {\left( {\frac{{{M_e}}}{{{M_m}}} \times \frac{{{g_m}}}{{{g_e}}}} \right)^{1/2}}$=${\left( {81 \times \frac{1}{6}} \right)^{1/2}}$
$\therefore$ ${R_e} = \frac{9}{{\sqrt 6 }}{R_m}$
Standard 11
Physics
Similar Questions
medium
