Page 44 - Q & A STPM 2022 Physics

Physics Semester 3 STPM Chapter 21 Sound Waves
Answer: B
A A
c
I
1
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I 2

From the above figure, l 2 – l 1 = (0.470 – 0.160) m = λ
2
Speed of sound, v = f λ = (512)(2 × 0.310) m s
–1
= 317 m s –1
Question 8
A stationary wave is formed inside a tube which is open at both ends. Which
diagram shows the locations of the node N and antinode A in the tube for the
first overtone?

A A N A C A N A N A

B N A N D N A N A N

Answer: C
Exam Tips
Exam Tips
Draw the stationary wave in the tube. Antinodes are found at the open ends.

A A A A A
N N N

Common Error

There is an antinode and not a node (N) at either of the open ends of the tube.
Semester
3 Then draw figures of the fundamental mode and the first overtone to get the
right answer.

404

021 STPM Q&A Physics T3.indd 404 17/02/2022 10:24 AM