DP Physics (last assessment 2024)
Question 18M.2.HL.TZ2.3b.ii
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.HL.TZ2.3b.ii |
| Level | HL | Paper | 2 | Time zone | TZ2 |
| Command term | Draw | Question number | b.ii | Adapted from | N/A |
b.ii.
[Maximum mark: 2]
18M.2.HL.TZ2.3b.ii
A loudspeaker emits sound towards the open end of a pipe. The other end is closed. A standing wave is formed in the pipe. The diagram represents the displacement of molecules of air in the pipe at an instant of time.
The loudspeaker in (a) now emits sound towards an air–water boundary. A, B and C are parallel wavefronts emitted by the loudspeaker. The parts of wavefronts A and B in water are not shown. Wavefront C has not yet entered the water.
(b.ii)
Draw lines on the diagram to complete wavefronts A and B in water for θ < θmax.
[2]
Markscheme
correct orientation
greater separation
Do not penalize the lengths of A and B in the water
Do not penalize a wavefront for C if it is consistent with A and B
MP1 must be awarded for MP2 to be awarded
[2 marks]