What will be the value of acceleration due to gravity on the surface of the earth if the radius of the earth suddenly decreases to 60% of its present value, keeping the mass of the earth unchanged ?
Answer & explanation
Correct answer: option 4
From Newton’s law of gravitation, we have ;
Gravitational Field : g = (Gx M1)/R2
Since the radius is reduced to 60% of its original value;
The new radius R’ = 0.6 x R
Therefore;
g’ = (G x M1)/(0.6*R)2
g’ = g/(0.6)2
= 9.81 / (0.6 x 0.6)
g’ = 27.25 m/s2.