Question 20N.3.SL.TZ0.7
| Date | November 2020 | Marks available | [Maximum mark: 5] | Reference code | 20N.3.SL.TZ0.7 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | 7 | Adapted from | N/A |
The first diagram shows a person standing on a turntable which can rotate freely. The person is stationary and holding a bicycle wheel. The wheel rotates anticlockwise when seen from above.
© International Baccalaureate Organization 2020.
The wheel is flipped, as shown in the second diagram, so that it rotates clockwise when seen from above.
© International Baccalaureate Organization 2020.
Explain the direction in which the person-turntable system starts to rotate.
[3]
«person rotates» anticlockwise ✓
the person gains angular momentum «in the opposite direction to the new wheel motion» ✓
so that the total angular momentum is conserved ✓
OWTTE
Award [1 max] for a bald statement of conservation of angular momentum
Explain the changes to the rotational kinetic energy in the person-turntable system.
[2]
the rotational kinetic energy has increased ✓
energy is provided by the person doing work «flipping the wheel» ✓
OWTTE
