Question

29. Two trains are approaching each other on a long straight track with constant
speed of v km/hr each. When the trains are l km. apart, a bird just in front of one
train flies at a speed w km/hr (w>v) towards the other train. When it arrives just in
front of that train, it turns and flies back towards the first train. In this way, it flies
back and forth between the two trains until the final moment when it is
sandwiched between the trains. Find the total distance travelled by the bird.​

Answer 1

Answer:

w/2v

Explanation:

the time after which the bird is sandwiched is given by

distance between trains initially ÷ relative velocity of trains

thus the time is 1/2v

and distance traveled by bird in this time interval is given by

velocity of bird × time for its sandwiching

thus

distance traveled by bird is

w×1/2v

=w/2v