A bird is flying to and fro between two cars moving with constant speeds on a straight smooth road. One car is moving at 18 km/h while other is moving towards the other at 27 km/h. The bird starts moving from the first car towards the other with a speed of 36 km/h when the distance of separation between the two is 36 km. What is the displacement of the bird when the two cars meet each other?

Options

A. 18 km
B. 22.6 m
C. 28.8 km
D. 30.2 km

Answer

c

Explanation

Here speed of first car
`v_1`=27km/h
Speed of second `v_2`=18km/h
As they are moving opposite to each other relavtive
Velocity of one w.r.t. to other
`=v_1+v_2=27+18`=45 km/h
`:.` Time required to meet `=(36)/(45)=0.8 hours`
Speed of the bird =36 km/h
`:.` Distance moved by the bird `=36xx0.8=28.8 km.`