Question 20N.2.HL.TZ0.a(i)
| Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.2.HL.TZ0.a(i) |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | State | Question number | a(i) | Adapted from | N/A |
A company delivers packages to customers using a small unmanned aircraft. Rotating horizontal blades exert a force on the surrounding air. The air above the aircraft is initially stationary.
The air is propelled vertically downwards with speed . The aircraft hovers motionless above the ground. A package is suspended from the aircraft on a string. The mass of the aircraft is and the combined mass of the package and string is . The mass of air pushed downwards by the blades in one second is .
State the value of the resultant force on the aircraft when hovering.
[1]
zero ✓
This was generally answered well with the most common incorrect answer being the weight of the aircraft and package. The question uses the command term 'state' which indicates that the answer requires no working.
