Question

If the earth lost 99% of its mass, the escape velocity would _____

(a) increase 10 times

(b) decrease 10 times

(c) decrease 90 times

(d) increase 90 times

I have been asked this question by my school principal while I was bunking the class.

My question is based upon Gravitation topic in division Gravitation of Physics – Class 11

Answer 1

The correct option is (b) decrease 10 times

Explanation: New mass of the earth (M’) = 0.01 x Original mass of the earth (M)

Therefore;

M’ = M/100

Escape velocity (v) is directly proportional to the square root of the mass

“v” is directly proportional to the square root of “M’”.

Therefore;

New escape velocity (v’) = v/10.