Question

the distance of the nearest point of lightning {speed of sound in air
= 346ms-¹​

Answer 1

Explanation:

answer for 1st part of question:

since the speed of light (300000 km/sec) is much greater than the speed of sound (346 m/s), we see the lightning first then we listen sound of the lightning.

remaining part of question i.e to measure the time interval by using stopwatch you have to do at your own.