A girl stand 80m away from a tall cliff and blows a whistle. If the speed of sound in air is 330ms-1, how long would it take for her to hear the echo of the sound?
-
A.
2.062s -
B.
0.970s -
C.
0.485s -
D.
0.242s
Correct Answer: Option C
Explanation
t = (frac{2x}{v} = frac{2 times 80}{330} = 0.485s)