A rider and equipment move down a cable. The table gives information about the journey. Take the gravitational field strength to be 10 N kg−110\ \mathrm{N\ kg^{-1}}10 N kg−1.
| Quantity | Value |
|---|---|
| Mass of rider and equipment | 60 kg |
| Vertical height descended | 5.0 m |
| Speed at the start of the descent | 2.0 m s−12.0\ \mathrm{m\ s^{-1}}2.0 m s−1 |
| Measured speed at the end of the descent | 9.0 m s−19.0\ \mathrm{m\ s^{-1}}9.0 m s−1 |
Calculate the speed at the end of the descent if no energy is transferred to the surroundings.
Calculate the energy transferred to the surroundings during the descent and explain where this energy goes.