Question

If a planet consists of a satellite whose mass and radius are both half that of earth. Acceleration due to gravity (g) at its surface should be :

Answer 1

Hey.

Here is the answer.

As g= GM / R^2...............on earth

but at that planet
M' = M/2
R'= R/2

so, g' = GM'/ R'^2 = 4GM/ 2 R^2 = 2GM/R^2

so, Acceleration due to gravity (g) at its surface should be twice that on the earth.

Thanks.

Answer 2

Answer:

19.6 m/s²

Explanation:

• Acceleration due to gravity, g=GM/R²
• g is proportional to M/R²

denote mass of earth as Me and that of other planet as Mp and radius as Re and Rp. acceleration due to gravity as ge and gp.

for planet ,Mp=Me/2

and Rp=Re/2

ge/gp=(Me/Mp)(Re/Rp)²

=1/2×2²=2

so gp=2×ge=2×9.8

=19.6m/s²