Question

A solid weighs 50 kg in the air and 44 kg when completely immersed in water calculate the relative density of the solid, upthrust and density of solid

Answer 1

Let m be the mass of the object.

Actual weight of the object, W = 50 gf = 50g N

Apparent weight of the object, Wa = 44 gf = 44g N

Let the buoyancy be B.

Now,

Wa = W – B

=> B = 50g – 44g

=> B = 6g N

This is the upthrust on the object.

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

Weight, W = Vdg = 50g

=> Vd = 50

The buoyancy is given by,

B = V(density of water)g

=> B = V(1000)g = 6g

=> V = 6/1000 = 0.006 m3

This is the volume of the object.

Now, Vd = 50

=> d = 50/V = 50/0.006

=> d = 8333.33 kg/m3

This is the density of the solid.