Question

What is the gravitational field intensity on the surface of a planet if its mass is doubled and radius is four times that of the earth? a.2/4 times that of the earth b.8 times that of the earth c.1/8 times that of the earth d.1/16 times that of the earth

Answer 1

Answer:

(c) 1/8 times that of the earth will be the answer.

Answer 2

Answer:

The gravitational acceleration at the surface is given by

g=GMr2

Where M is the planet’s mass and r its radius. Letting ME and rE be the mass and radius of the Earth, we have:

gE=GMEr2E

And you want to calculate

G2ME(4rE)2

G2ME(4rE)2=2GME16r2E=18GMEr2E=gE8

or 1/8 g, about 3/4 the gravity on the Moon. Since gE=9.8 m/s 2 , so the gravitational acceleration would be 1.225 m/s 2

Explanation:

This is the correct answer