Question 19N.3.SL.TZ0.5b(i)
| Date | November 2019 | Marks available | [Maximum mark: 1] | Reference code | 19N.3.SL.TZ0.5b(i) |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Identify | Question number | b(i) | Adapted from | N/A |
A flywheel is made of a solid disk with a mass M of 5.00 kg mounted on a small radial axle. The mass of the axle is negligible. The radius R of the disk is 6.00 cm and the radius r of the axle is 1.20 cm.
A string of negligible thickness is wound around the axle. The string is pulled by an electric motor that exerts a vertical tension force T on the flywheel. The diagram shows the forces acting on the flywheel. W is the weight and N is the normal reaction force from the support of the flywheel.
The moment of inertia of the flywheel about the axis is .
The flywheel is initially at rest. At time t = 0 the motor is switched on and a time-varying tension force acts on the flywheel. The torque exerted on the flywheel by the tension force in the string varies with t as shown on the graph.
Identify the physical quantity represented by the area under the graph.
[1]
«change in» angular momentum ✔
NOTE: Allow angular impulse.
