Question

The speed of sound is 346 m/s. If during a thunderstorm the sound of lightning is heard 10
seconds after the flash, then how far is the thunderstorm from you?
A
5 km
B
6 km
C
3.46 km
D 7.55 km​

Answer 1

Answer:

Lightning and thunder are produced simultaneously, but the thunder is heard a few seconds after the lightning is seen. This is because the speed of light in air is more than the speed of sound in air.

The speed of light is given as 3×10

8

m/s. The speed of sound is 340 m/s. Thus, the entire time of 10 seconds (as mentioned in the question) between seeing the light and hearing the thunderstorm is taken by the sound to travel to the observer. Hence, the distance traveled by the thunder is given as follows.

s=vt; where,

s is the distance traveled, v is the velocity of sound and t is the time taken.

That is, 330m/s×10s=3400m=3.4km.

Thus, the distance traveled by the thunder is 3.4km.

Answer 2

Answer:

as we know distance is equal to s×t , that is speed multiplied with time then ;

distance = 346 × 10

= 3460 m or 3.46m

so the answer is option c