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
Correct Answer: Option B
Explanation
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