Question

A new planet is discovered that has twice the Earth's mass and twice the Earth's radius. On the surface of this
new planet, a person who weighs 500 N on Earth would experience a gravitational force of
(A) 125 N (B) 250 N (C) 500 N (D) 1000 N

Answer 1

Answer:

1000

Explanation:

500*2=1000

Because

ATP

the mass of the new plannet is twice and the radius is also twice

Answer 2

On the surface of the new planet , person will experience a force of 250N.

•) Let mass of Earth be M and radius of earth be R.

Now we know that , acceleration due to gravity on earth ie g is

g = GM / R^2 ---------(1)

Where, G is the gravitational constant .

•) Now let g' be the acceleration due to gravity , M' be the mass and R' be the radius of that new planet.

•) Now it is given that

M' = 2M , R' = 2R

Hence ,

g' = GM' / R'^2

g' = 2*GM / 4R^2 = ½g [using (1)]

•) Now , weight of the person on Earth is 500N , hence mass of that object will be 50Kg.

Now on that new planet , weight of the person will be.

W' = 50*½g = ½*500 = 250N