A bird flies to and fro between two cars which moves with velocities `v_1 = 20 m//s and v_2 = 30 m//s`. If the speed of the bird is `v_3 = 10 m//s` and the initial distance of separation between them is `d = 2 km`, find the total distance covered by the bird till the cars meet.

Options

A. 2000 m
B. 1000 m
C. 400 m
D. 200 m

Answer

C

Explanation

Time to meet the cars : `t = (d)/(v_1 + v_2)`
Distance travelled by bird in this time
`s = v_3 t = (v_3 d)/(v_1 + v_2) = (10 xx 2000)/((20 + 30)) = 400 m`.