Question

A solid weighs 50g in air and 44g when completely immersed in water . Calculate
A. The upthrust
B. The volume of solid
C. Relative density of the solid

Answer 1

Dear Student,

Let m be the mass of the object.

Actual weight of the object, W = $50\times {10}^{-3}\times 10=0.5\mathrm{N}$

Apparent weight of the object, W_a = $44\times {10}^{-3}\times 10=0.44\mathrm{N}$

Let the buoyancy be B.

Now,

W_a = W – B

=> B = 0.5 – 0.44

=> B = 0.06 N

This is the upthrust on the object.

Let ‘d’ be the density of the object, and ‘V’ be its volume.

Weight, W = Vdg = 0.5

=> Vd = 0.05

The buoyancy is given by,

B = V(density of water)g

=> B = V(1000)10 = 0.06

=> V = 0.06/10000 = 0.000006 m³

This is the volume of the object.

Now, Vd = 0.05

=> d = 0.05/V = 0.05/0.000006

=> d = 8333.33 kg/m³

This is the density of the solid.