Topic: Fluid Mechanics
If a jet of water of area 'A' strikes with velocity 'V' a series of flat plates mounted on a wheel of mean diameter D rotating at N rpm, then force exerted will be equal to
- A. $\frac{\rho AV^{2}}{g}$
- B. $\frac{\rho AV}{g}(V-\frac{\pi DN}{60})$
- C. $\frac{\rho A}{g}\times\frac{\pi DN}{60}$
- D. $\frac{\rho A}{g}(V-\frac{\pi DN}{60})$
Answer: B. $\frac{\rho AV}{g}(V-\frac{\pi DN}{60})$
Explanation: Force Exerted $= \frac{\rho AV(V-u)}{g}$ [Force per unit weight] where $u=\frac{\pi DN}{60}$. Therefore, Force $= \frac{\rho AV}{g}[V-\frac{\pi DN}{60}]$.