Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine?
| 1. | 12.3 kW | 2. | 7.0 kW |
| 3. | 10.2 kW | 4. | 8.1 kW |
| 1. | \(\left(2 t^2+4 t^4\right)~\text W\) | 2. | \(\left(2 t^3+3 t^3\right) ~\text W\) |
| 3. | \(\left(2 t^3+3 t^5\right) ~\text W\) | 4. | \(\left(2 t^3+3 t^4\right) ~\text W\) |
| 1. | \( \sqrt{\frac{m k}{2}} t^{-1 / 2} \) | 2. | \( \sqrt{m k} t^{-1 / 2} \) |
| 3. | \( \sqrt{2 m k} t^{-1 / 2} \) | 4. | \( \frac{1}{2} \sqrt{m k} t^{-1 / 2}\) |
A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude \(P_0\). The instantaneous velocity of this car is proportional to:
| 1. | \(t^{\frac{1}{2}}\) | 2. | \(t^{\frac{-1}{2}}\) |
| 3. | \(\frac{t}{\sqrt{m}}\) | 4. | \(t^2 P_0\) |