Question

The mass of the moon is `1/81` of the mass of the earth. Its diameter is `1/3.7` of that of the earth. If acceleration due to gravity on the surface of the earth is 9.8 m/s², then the acceleration due to gravity on the surface of the moon.

Options

• 9.8 x 6 m/s²

• `9.8/6` m/s²

• `9.8/3` m/s²

• 9.8 x 3 m/s²

Answer 1

`9.8/6` m/s²

Explanation:

g = `"GM"/"R"^2` and `"g"_"m"/"g"_"e" = ("M"_"m")/("M"_"e") xx ("R"_"e"^2)/("R"_"m"^2) = 1/81 xx ((3.7)/1)^2 ≅ 1/6`

Hence g_m = `"g"_"e"/6 = 9.8/6` m/s²