Question

The radius of earth is 6370Km and of mars is 3400 Km. If an object weighs 200N or earth, what will be its weight on mars. The mass of mars is 0.11 that of earth.

Answer 1

Let the mass of earth and the mass of the body are m₁ and m respectively. Also let, g' is the gravitational acceleration on the mars.
Then the mass of mars is =0.11m₁.
Radius of earth=r₁=6370km
Radius of mars=r₂=3400km
 Weight of the body on earth is 200N.
∴, mg'=Gm₁m/(r₂)²
or, mg'=G×0.11m₁m/(3400)²×(r₁²/r₁²)
or, mg'={(0.11×r₁²)/3400²}×(Gm₁m/r₁²)
or, mg'=(0.11×6370²×200)/(3400)²
or, mg'=(0.11×6370×6370×200)/(3400×3400)
or, mg'=(22×637×637)/(34×3400)
or, mg'=8926918/115600
or, mg'=77.22N