question_answer

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:       [AIPMT (S) 2005]

A) \[g'=3\,g\]

B) \[g'=\frac{g}{9}\]

C) \[g'=9\,g\]

D) \[g'=27\,g\]

Correct Answer: A

Solution :

The acceleration due to gravity on the new planet can be found using the relation

(i)

but  being density

Thus, Eq. (i) becomes