Question

sound of thunder is heard 5 sec after the flash of lighting in seen calculate the distance of nearest point of lightning if the speed of sound in air is 346 m/s

Answer 1

here you can use the simplest formula,
speed=distance÷time
distance=speed ×time
distance=346×5
distance=1730m
Hence the nearest distance lightning would strike is 1730m or 1.7Km


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Hope this helps you.

Answer 2

D=s*t

D=346*5=1730 m

Or

1 km 730 m