Two different descent systems are tested for emergency radio beacons released vertically from a high platform. Each beacon is released from rest.
The table gives measurements from the tests. "Not recorded" means that the value must be calculated.
| Descent system | Mass of beacon / kg | Vertical release height / m | Speed immediately before landing / m/s | Energy dissipated during descent / J |
|---|---|---|---|---|
| R | 5.0 | Not recorded | 10.0 | 1750 |
| S | 5.0 | 36 | 8.0 | Not recorded |
Gravitational field strength (ggg) = 10 N/kg
Calculate the vertical release height used in the test with descent system R.
The descent system will be selected only if the beacon lands at a speed of no more than 9.0 m/s and at least 1600 J is dissipated during the descent. Evaluate which descent system should be selected. Use numerical evidence from the table and your calculation.
A third beacon has a mass of 6.0 kg. It is released from rest from a vertical height of 36 m. During the descent, 1500 J is dissipated. Calculate the speed of this beacon immediately before landing.