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Two trains A and B 100 m and 60 m long a...

Two trains A and B 100 m and 60 m long are moving in opposite direction on parallel tracks. The velocity of the shorter train is 3 times that of the longer one. If the trains take 4s to cross each other, the velocities of the trains are

A

`v_(A) = 10ms^(-1), v_(B) = 30ms^(-1)`

B

`v_(A) = 2.5 ms^(-1), v_(B) = 7.5 ms^(-1)`

C

`v_(A) = 20ms^(-1), v_(B) = 60ms^(-1)`

D

`v_(A) = 5ms^(-1), v_(B) = 15ms^(-1)`

Text Solution

Verified by Experts

The correct Answer is:
A
`3_(v_(A)) = v_(B), " "v_("rel") = V_(A) + V_(B)`
`t = (1_(A) + 1_(B))/(v_("rel")), " "s_(1) + s_(2) = (v_(A) + v_(B))t`
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