Question

Two trains, each travelling with a speed of 37.5 k m h^{-1},37.5kmh−1, are approaching each other on the same straight track. A bird that can fly at 60 \mathrm{kmph}60kmph flies off from one train when they are90 \mathrm{km}90km apart and heads directly for the other train. On reaching the other train, it flies back to the first and so on. Total distance covered by the bird before trains collide is


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Answer 1

Given :-

• Speed of Both Both Trains = 37.5 km/h .
• Speed of bird = 60km/h .
• Distance between both trains = 90km.
• The bird that flies off from one train and heads directly for the other train. On reaching the other train, it flies back to the first and so on.

To Find :-

• Total distance covered by the bird before trains collide is ?

Solution :-

→ Speed of first train = 37.5km/h .

→ Speed of second train = 37.5km/h .

So,

→ Relative Speed of both trains = S1 + S2 (Opposite direction.)

→ Relative speed = 37.5 + 37.5 = 75km/h.

Now,

→ Distance between both trains = 90km.

So,

→ Time taken before trains collide = Distance/Relative speed = (90/75) = (6/5) Hours.

Also,

→ Speed of bird = 60km/h .

→ Time for which bird will fly = (6/5) hours.

Therefore,

→ Total Distance covered by bird = Speed * Time = 60 * (6/5) = 72km (Ans.)

Hence, Total distance covered by the bird before trains collide is 72km.

Answer 2

Step-by-step explanation:

Given Two trains, each travelling with a speed of 37.5 kmh−1, are approaching each other on the same straight track. A bird that can fly at 60 kmph flies off from one train when they are 90 km apart and heads directly for the other train. On reaching the other train, it flies back to the first and so on. Total distance covered by the bird before trains collide is

• Consider two trains train 1 and train 2
• Speed of both trains is 37.5 km/hr  
• Relative velocity of train = v1 + v2
•                                          = 37.5 + 37.5
•                                          = 75 km/hr
• So time taken by the train to cross each other will be
•                                    Time = distance / velocity
•                                              = 90 kms / 75 km/hr
•                                                = 1.2 hrs
• Now distance travelled by the bird will be velocity x time
•                                                                    = 60 km/hr x 1.2 hrs
•                                                                    = 72 kms
• Therefore distance travelled by the bird when both trains collide will be 72 kms

Reference link will be

https://brainly.in/question/118357