Question

a body weighs 90 kg weight on the surface of mass will be mass of mars 1/9 mass of earth radius of mars 1/2 radius of earth

Answer 1

$<b>$Acceleration due to gravity is calculated as
a = GM / R²
Where M = Mass of Planet and R is radius of Planet.

For earth
9.8 = GM / R² …………(1)

For Mars
g = G × (M/9) / (R / 2)²
g = (4/9) × GM / R²
g = (4/9) × 9.8 ………[∵ from (1)]
g = 4.35 m/s²

Now,
Weight of body = mg
= 90 kg × 4.35 m/s²
= 392 N

Weight of 90 kg body on surface of Mars is 392 N

[Note: If weight of body on surface of earth is 90 N then on surface of Mars it’s weight is 90 × 4/9 = 40 N]

Answer 2

Explanation:

<b> Acceleration due to gravity is calculated as

a = GM / R²

Where M = Mass of Planet and R is radius of Planet.

For earth

9.8 = GM / R² …………(1)

For Mars

g = G × (M/9) / (R / 2)²

g = (4/9) × GM / R²

g = (4/9) × 9.8 ………[∵ from (1)]

g = 4.35 m/s²

Now,

Weight of body = mg

= 90 kg × 4.35 m/s²

= 392 N

Weight of 90 kg body on surface of Mars is 392 N

[Note: If weight of body on surface of earth is 90 N then on surface of Mars it’s weight is 90 × 4/9 = 40 N]