Can someone explain how to tackle it, please?
Please follow the link for the question and its graph:
http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20%289702%29/9702_w11_qp_12.pdf
Please follow the link for the question and its graph:
http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20%289702%29/9702_w11_qp_12.pdf
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Well you don't make it easy! There are 40 questions. Why not give the question number?
I guess you mean Q26 as it is the only waves question with a graph.
After 18s:
- the upper wave has performed 4 complete cycles (count from peak to peak);
- the lower wave has performed 4.5 complete cycles.
That means:
- over 18s the waves become 1/2 cycle out of phase
so by proportion
- over 9s the waves become 1/4 cycle out of phase
- over 4.5s the waves become 1/8 cycle out of phase (answer B)
I guess you mean Q26 as it is the only waves question with a graph.
After 18s:
- the upper wave has performed 4 complete cycles (count from peak to peak);
- the lower wave has performed 4.5 complete cycles.
That means:
- over 18s the waves become 1/2 cycle out of phase
so by proportion
- over 9s the waves become 1/4 cycle out of phase
- over 4.5s the waves become 1/8 cycle out of phase (answer B)