A stream-lined body falls through air from a | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) The velocity $u$ of the body when it enters the liquid is given by conservation of energy:$mgh = \frac{1}{2} mu^2 \implies u = \sqrt{2gh}$Let $V$

Vedclass · Accepted Answer

$\sqrt{\frac{2h}{g}} \left( \frac{d}{D-d} \right)$

Vedclass · Answer

(D) The velocity $u$ of the body when it enters the liquid is given by conservation of energy:$mgh = \frac{1}{2} mu^2 \implies u = \sqrt{2gh}$Let $V$ be the volume of the body.Mass of the body $m = Vd$.Weight of the body $W = Vdg$.Buoyant force $F_B = VDg$.Net upward force $F_{net} = F_B - W = Vg(D-d)$.Retardation $a = \frac{F_{net}}{m} = \frac{Vg(D-d)}{Vd} = \left( \frac{D-d}{d} \right) g$.Since the body is moving downwards, the acceleration is $a' = -\left( \frac{D-d}{d} \right) g$.Using the equation of motion $v = u + a't$, where $v = 0$ at the point of instantaneous rest:$0 = \sqrt{2gh} - \left( \frac{D-d}{d} \right) gt$$t = \left( \frac{d}{D-d} \right) \sqrt{\frac{2h}{g}}$

$A$ stream-lined body falls through air from a height $h$ on the surface of a liquid. Let $d$ and $D$ denote the densities of the materials of the body and the liquid respectively. If $D$ > $d$, then the time after which the body will be instantaneously at rest is

Similar Questions

Find the apparent weight of a metallic block of density $5 \text{ g cm}^{-3}$ and dimensions $5 \text{ cm} \times 5 \text{ cm} \times 5 \text{ cm}$,in water.

$A$ body floats in a liquid contained in a beaker. The whole system falls freely under gravity. The upthrust on the body due to the liquid is

$A$ block of steel of size $5 \text{ cm} \times 5 \text{ cm} \times 5 \text{ cm}$ is weighed in water. If the relative density of steel is $7$,its apparent weight is:

In which case does the potential energy decrease?

Vedclass Test Series

Exam Paper Generator

Online Exam Module