During a thunderstorm, lightning and thunder occurred simultaneously in the atmosphere. An observer on the earth surface's sees the lightning flash shortly before hearing the thunder. This is because the
A.
atmospheric pressure is higher at the surface than at the higher altitudes
B.
speed of sound is less than that of light
C.
temperature of the atmosphere decreases with altitude
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?