Question

Two spheres A and B ,each of volume 100cm^3are placed in water.The sphere A is made up of density 0.3cm^-3and the sphere B is of density 8.9g cm^-3. Find the upthrust on each sphere​

Answer 1

Explanation:

Density of water = Dw.

Volume immersed = Vi

Acceleration due to gravity = g

Upthrust on A = Dw × Vi × g

Da = Density of Sphere A.

Va = Volume of Sphere A.

Vi = Da × Va / Dw

$= \frac{0.3 \times 100}{1} = 30 \: {cm}^{3}$

$upthrust = 1 \times 30 \times 10 = 300 \: n$

Upthrust on A is 300 N.

Upthrust on B = Dw × Vi × g

Db = Density of Sphere B.

Vb = Volume of Sphere B.

Vi = Db × Vb / Dw

$= \frac{8.9 \times 100}{1} = 890 \: {cm}^{ 3}$

$upthrust = 1 \times 890 \times 10 = 8900 \: n$

Therefore, Upthrust on B is 8900 N.

I hope it helps you. If you have any doubts, then don't hesitate to ask.