Balance on a bicycle is a matter of constantly correcting against falls, and it's easier when the speed is higher because the inertia of moving forward overcomes the need for corrective actions.
Time taken (t) = 3 sec
Velocity of sound (v) = 332 m/s
Distance travelled (d) = ?
We know,
d = v x t = 332 x 3 = 996 m
Hence, the source of thunder is about 996 m far from the boy.
This picture develops a clear understanding.

The Wheatstone bridge is not suitable for measuring very low resistance because it is based on a ratio of two resistances, and the resolution of the bridge decreases as the ratio approaches 1. This means that the Wheatstone bridge is not accurate enough to measure very small changes in resistance.
If a vector A is multiplied by a real number (say n), the vector of same nature is obtained but its magnitude is n times that of A.
routine of nikas banda