Question

A block floats partially submerged in a container of liquid. When the entire container is accelerated upward, which of the following happens? Assume that both the liquid and the block areincompressible.
(A) The block descends down lower into the liquid.(B) The block ascends up higher in the liquid.(C) The block does not ascend nor descend in the liquid.
(D) The answer depends on the direction of motion of the container.(E) The answer depends on the rate of change of the acceleration

Answer 1

Answer:C

Explanation:

Partially submerged block along with vessel is accelerated upwards .

Initially the block weight is supported by buoyant force such that it is in equilibrium.

when the system start accelerating upwards then the effective gravity will be

g+a where a is the acceleration of the system.

so only net gravity is increased so block will not ascend or descend.

Mathematically

$F_b=weight$

$\rho _L\cdot V\cdot (g+a)=m(g+a)$

where $\rho _L=$density of liquid

V=volume of object inside the water