## neoh147 3 years ago Two trains, each having a speed of 30 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching the other train, the bird flies directly back to the first train, and so forth. What is the total distance the bird travels before the trains collide?

1. neoh147

i know the answer is 60km.. but how to show??

2. A.Avinash_Goutham

so the bird start flying wen they are 60 km apart..

3. neoh147

ya

4. A.Avinash_Goutham

ok let's do it the smart way.......if u r sitting on the first train and u see the second train........wat wud be it's speed? like rate f approach r wateva

5. neoh147

relative speed.. if i'm in train A, i will see train B moving with 60km/h toward me...

6. A.Avinash_Goutham

yea nd that bird?

7. neoh147

moving with 30km/h away frm me

8. A.Avinash_Goutham

yea.....so u got a train 60 km away nd moving towards u @ 60 kmph and a damn bird moving away @ 30kmph........so u wanna find wen that bird reaches the train

9. neoh147

half hour..meet at 30km position..

10. neoh147

i think i get the idea ald.. thx a lot A.Avinash... just using the relative speed of both train n bird toward me.. n i look like resting.. thn i use the total time for calc the actual distance of the bird...

11. A.Avinash_Goutham

well ok then