MCQEasy1 mark
20
Select the correct option for each of the following questions A boy standing in front of a wall produces two whistles per second. He notices that the sound of his whistling coincides with the echo. The echo is heard only once when whistling is stopped. Calculate the distance between the boy and the wall. (The speed of sound in air = 320 m/s)
The distance at which the boy is standing from the wall: (a) 160 m (b) 240 m (c) 320 m (d) 80 m
Topic: Heat and calorimetry
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Pick an option and check your answer. The full worked answer is below either way.
Answer
Exam answer
(d) 80 m.
Explanation
d=vt/2=320×0.5/2=80 m.
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