A girl standing some distance from the cliff claps her hands and hears the echo 0.8s later. calculate her distance from the cliff. [speed of sound in air = 320 ms-1]
A
23m
B
128m
C
288m
D
298m
Verified Correct Answer: B.
Physical Principles & Numerical Solution
V = \(\frac{2nx}{E}\)
= \(\frac{2 \times 1 \times X}{0.8} = 320\)
2x = 0.8 x 320
x = \(\frac{0.8 \times 320}{2}\)
= 128m
Source: Myschool Past Questions Archive (Record #45503)