Fluid Mechanics Viscosity Question 76

Question: A body floats in a liquid contained in a beaker. The whole system as shown falls freely under gravity. The upthrust on the body due to the liquid is [IIT-JEE 1982]

Options:

A) Zero

B) Equal to the weight of the liquid displaced

C) Equal to the weight of the body in air

D) Equal to the weight of the immersed position of the body

Show Answer

Answer:

Correct Answer: A

Solution:

Upthrust $ =V{\rho_{r}}(g-a) $ where, a = downward acceleration, V = volume of liquid displaced But for free fall a = g $ \therefore $ Upthrust = 0