the weight of a body on the surface of earth is 392n.what is the mass when g=9.8m/s.if the body is taken to moon, it weighs 64n.what is the mass of a body on the moon?calculate the gravity on moon?

we know that the weight is given as

W = mg

or the mass 

m = W/g

here, on earth

W = 392 N

g = 9.8 m/s²

so,

m = 392 / 9.8

thus, mass of body in earth will be

m = 40kg

now,

the mass of body will remain constant everywhere, so on the moon it will also be 40kg

now, for moon we have

W' = mg'

or the gravitational acceleration on moon 

g' = W'/m

here,

W' = 64N

so,

g' = 64/40

thus, we get

g' = 1.6 m/s²