passwella.
Menu

JAMB Physics 1978 Question 41

Question 41

Sound

A herdsman yelling out to fellow herdsman heard his voice reflected by a cliff 4 s later. What is the velocity of sound in air if the cliff is 680 m away?

  1. A.170 m s−1
  2. B.136 m s−1
  3. C.340 m s−1
  4. D.680 m s−1
  5. E.510 m s−1.
Show the answer and explanation

Answer: C (340 m s−1)

Explanation

The echo travels to the cliff and back, 2 × 680 = 1360 m, in 4 s, so v = 1360/4 = 340 m s−1.