9th Class Science Gravitation and Floatation Question Bank Gravitation

  • question_answer
    What will be the acceleration due to gravity on the surface of moon if its radius is \[\frac{1}{4}\]th the radius of the earth and its mass is \[\frac{1}{80}\] th the mass of earth?

    A)  \[\frac{g}{2}\]                 

    B)         \[\frac{g}{3}\]

    C)  \[\frac{g}{7}\]                 

    D)         \[\frac{g}{5}\]  

    Correct Answer: D

    Solution :

     We know,          \[g=\frac{G{{M}_{e}}}{{{R}_{e}}2}\] and                        \[g'=\frac{G{{M}_{m}}}{{{R}_{m}}2}\] \[\therefore \]                  \[\frac{g'}{g}=\frac{{{M}_{m}}}{{{M}_{e}}}{{\left( \frac{{{R}_{e}}}{{{R}_{m}}} \right)}^{2}}\]                 \[=\frac{1}{80}\times {{\left( \frac{4}{1} \right)}^{2}}=\frac{1}{5}\] \[\Rightarrow \]    \[g'=\frac{g}{5}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner