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A 100 m long train is travelling from No...

A 100 m long train is travelling from North to South at a speed of `30ms^(-1)`. A bird is flying from South to North at a speed of `10ms^(-1)`. How long will the bird take to cross the train?

A

3s

B

2.5s

C

10s

D

5s

Text Solution

Verified by Experts

The correct Answer is:
B
Length of train = 100 m
Bird and train are moving in a opposite direction
`:.` Relative velocity `=30+10=40ms^(-1)`
Time taken to cross the train (t) `=("distance")/("R.velocity")=(100)/(40)=2.5s`.
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