Question 436: Gravitation

Question

Imagine a new planet having the same density as that of earth but it is 3 times bigger than the earth in size. If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet is g', then

Accepted Answer

We know that
$$g = {{GM} \over {{R^2}}} = {{G\left( {{4 \over 3}\pi {R^3}} ight)} \over {{R^2}}} = {4 \over 3}\pi GRho $$
$${{g'} \over g} = {{R'} \over R} = {{3R} \over R} = 3$$
$$ 	herefore $$ g' = 3g

Answer

g' = g/9

Answer

g' = 27g

Answer

g' = 9g

Answer

g' = 3g

Gravitation

Imagine a new planet having the same density as that of earth but it is 3 times bigger than the earth in size. If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet is g', then

Choose the correct answer: