Question 19M.2.HL.TZ1.a.ii
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.HL.TZ1.a.ii |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Show that | Question number | a.ii | Adapted from | N/A |
Show that the tension T in the string is
[1]
use of T = MR to find T = MR × ✔
«cancelling to show final answer»
This simple system of a solid cylinder rotating about a fixed axle and a block hanging on the rope accelerating proved to be rather difficult for many candidates. Only the best candidates were able to solve this problem, by writing two separate equations, and then solving to establish the acceleration of the system. The use of energy conservation was not a common technique attempted by students. As this is a “show that” question, candidates were asked to show that the angular acceleration is equal to g/(3R). Quite a high number of candidates successfully used the equations of motion and a similar number used the moment of inertia of the block around the axle. In ii), well-prepared candidates used the angular acceleration of the cylinder from i) and the tension expression to arrive at the given Mg/6.
