Find the distance of cloud from you when you hear a thunder 3 s after the lightning is seen. Given, speed of light =3xl08 ms-1, speed of sound = 330 ms -1. Why is lightning seen a four seconds before the thunder is heard duirng a thunders storm?
Given, time, t = 3 s
Speed of sound in air = 330 m/s
Therefore, the distance from the cloud will be
calculated as
Distance = Speed x Time = 330 x 3 = 990 m
As the speed of light in air (i.e. 3 x ${{10}^{8}}$m/s) is much greater than the speed of sound in air (i.e. 340 m/s). So, this is a reason why lightning is seen a four seconds before the thunder is heard during thunderstorm.