Question

The mass of a body on earth is 10 kg. Find its weight on a planet whose mass is twice the mass of the earth and radius of planet is twice the radius of the earth.

Answer 1

For earth :
If mass of earth is= M Radius of earth= R
and the mass of body on earth is=m
then weight of body on earth can be written as
W= gMm/R²

For other planet:
If mass is twice than the earth= 2M
, Radius is 2 times= 2R
then mass of the body can be found as:
W= g(2M)(m)/(2R)²
W=(2/4)(gMm/R²)
Mass of earth and radius has value of earth so taken as 1 value of gravity is 9.8 and mass of body is 10 so:
W=(2/4)(10× 9.8)
W= 49 N
So if body is of 10 kg on earth its mass on the the other planet will be 2
49 N