Moving water can be used to generate electricity using a tidal stream turbine.
Figure 1 shows a graph of kinetic energy against water speed for a constant mass of moving water flowing past the turbine site.
| Water speed (m/s) | Kinetic energy (kJ) |
|---|---|
| 0 | 0 |
| 1 | 0.4 |
| 2 | 1.6 |
| 3 | 3.6 |
| 4 | 6.4 |
| 5 | 10.0 |
Just before the water reaches the tidal turbine it has a speed of 5.0 m/s.
When the water has gone through the turbine, it has slowed down to a speed of 4.0 m/s.
As the water moves through the turbine, some of its kinetic energy is transferred to the turbine to generate electricity.
Use the information in Figure 1 to determine the percentage of the kinetic energy transferred to the turbine from the water.