Question

1. A boy fires a gun and hears the echo 2 seconds later. If he is 350 m away from a wall, calculate the velocity of sound in air.
2. A girl claps and hears the echo after reflection from a cliff which is 660 m away from her. If the velocity of sound is 330 m/s, calculate the time taken for hearing the echo.

please help me....​

Answer 1

Answer:

1

$v = \frac{2d}{t} \\ d = 350m \\ t = 2s \\ v = (2 \times 350 )\div 2 \\ = 350ms^{ - 1}$

2

$v = \frac{2d}{t} \\ 330 = \frac{2 \times 660}{t} \\ 330 \times t = 660 \times 2 \\ t = \frac{660 \times 2}{330} \\ t = 4s$