Gujarati
Hindi
9-1.Fluid Mechanics
medium

Water coming out of a horizontal tube at a speed ? strikes normally a vertically wall close to the mouth of the tube and falls down vertically after impact. When the speed of water is increased to $2v$ .

A

the thrust exerted by the water on the wall will be doubled

B

the thrust exerted by the water on the wall will be four times

C

the energy lost per second by water striking the wall be increased eight times.

D

$B$ and $C$ both

Solution

Thrust $=$ Rate of charge of linear momentum

Thrust $=\mathrm{mv}$ where $\mathrm{m}$ is mass striking per sec.

$=\rho a v \times v \Rightarrow \quad$ Thrust $=\rho a v^{2}$

Energy lost for second $=\frac{1}{2} m v^{2}=\frac{1}{2} \rho a v . v^{2}=\frac{1}{2} \rho a v^{3}$

so option $(\mathrm{B}, \mathrm{C})$ are correct.

Standard 11
Physics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.