Question

A steam of water flowing horizontally with a speed of $vm/s$ gushes out of a tube of cross sectional area $A{m}^2$,and hits at a vertical wall nearby. What is the force exerted by the impact of water, assuming that water rebounds with the same speed.

Answer 1

Force $=dP/dt$

$⟹$ Change in momentum per unit time $=m^{.}(v-(-v\left)\right)$

Now $m=\rho Av$

Hence Force exerted equal to $\rho Av\times 2v$ => $F=2\rho A{v}^2$