Question 19M.3.HL.TZ2.14c
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.HL.TZ2.14c |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Draw | Question number | c | Adapted from | N/A |
A railway track passes over a bridge that has a span of 20 m.
The bridge is subject to a periodic force as a train crosses, this is caused by the weight of the train acting through the wheels as they pass the centre of the bridge.
The wheels of the train are separated by 25 m.
The graph shows the variation of the amplitude of vibration A of the bridge with driving frequency fD, when the damping of the bridge system is small.
The damping of the bridge system can be varied. Draw, on the graph, a second curve when the damping is larger.
[2]
similar shape with lower amplitude ✔
maximum shifted slightly to left of the original curve ✔
Amplitude must be lower than the original, but allow the amplitude to be equal at the extremes.
A correct curve, with lower amplitude and shifted left, was drawn by most candidates.
