Answer
Given,
Time to hear the clap = 14.4 s
speed of the light = 3 x 10⁸ m/s
Speed of sound = 343 m/s
a) distance where lightning strike
D = s x t
D = 14.4 x 343
D = 4939.2 m
b) No, we do not need to know the value of speed of light. Because we need to calculate the distance where we hear the sound. To calculate that we need to know the speed of sound.