Question

The mass of the moon is 1/81 of earth's mass and it's radius 1/4 that of these earth. If the escape velocity from the earth's surface is 11.2km/sec, its value for the earth's surface

Answer 1

Hello Dear,

Escape velocity from earths surface is already given. You may want to ask escape velocity from moons surface.

● Answer -

Escape velocity from moon's surface = 2.489 km/s

● Explanation -

Escape velocity from earth's surface is given by formula -

ve = √(2GM/R)

For moon this will be,

ve' = √(2GM'/R')

Taking ratio,

ve'/ve = √(2GM/R') / √(2GM/R)

ve'/ve = √(RM') / √(MR')

ve'/ve = √(RM/81) / √(MR/4)

ve' = ve × √(4/81)

ve' = 11.2 × 2/9

ve' = 2.489 km/s

Therefore, escape velocity from moons surface is 2.489 km/s.

Thanks dear...