Question

a solid sphere weighs 40 N in water and 45N in a liquid of relative density 0.75 when completely immersed . the weight of sphere in air will be.

Answer 1

the weight of the object is 60N

Answer 2

Dear Student,

◆ Answer -

Weight of sphere in air = 60 N

● Explanation -

Let W be weight of sphere in the air.

Weight in water is -

W' = W - ρwVg

40 = W - 1×Vg

Vg = W - 40 ...(1)

Weight in liquid is -

W" = W - ρwVg

40 = W - 0.75×Vg

0.75Vg = W - 45

Vg = W/0.75 - 45/0.75

Vg = 4W/3 - 60 ...(2)

Equating (1) and (2),

W - 40 = 4W/3 - 60

4W/3 - W = 60 - 40

W/3 = 20

W = 20×3

W = 60 N

Hence, weight of sphere in air is 60 N.

Thanks dear. Hope this helps you...