MCQ
If the mass of earth is $80$ times of that of a planet and diameter is double that of planet and $‘g’$ on earth is $9.8\,m/{s^2}$, then the value of $‘g’ $ on that planet is ........ $m/{s^2}$
- A$4.9$
- B$0.98$
- ✓$0.49$
- D$49$
✓
Answer
Correct option: C.
$0.49$
c
(c) ${g_p} = {g_e}\,\left( {\frac{{{M_p}}}{{{M_e}}}} \right)\,{\left( {\frac{{{R_e}}}{{{R_p}}}} \right)^2} = 9.8\,\left( {\frac{1}{{80}}} \right)\,{(2)^2}$
(c) ${g_p} = {g_e}\,\left( {\frac{{{M_p}}}{{{M_e}}}} \right)\,{\left( {\frac{{{R_e}}}{{{R_p}}}} \right)^2} = 9.8\,\left( {\frac{1}{{80}}} \right)\,{(2)^2}$
$ = 9.8/20 = 0.49\,\,m/{s^2}$
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