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If two trains A & B are moving with speed v, what will be the value of the relative velocity of train A with respect to train B if they are moving toward each other?

If two trains A & B are moving with speed v, what will be the value of the relative velocity of train A with respect to train B if they are moving toward each other? Correct Answer 2v

Concept:

The concept of relative velocity occurs when we encounter occasions where one or more objects move in a frame which is non-stationary concerning another observer where the relative velocity is the velocity of an object or observer B in the rest frame of another object or the observer A.

In simple terms, velocity is not always a fixed definite quantity it may change from one frame of reference to another.

If an object is travelling in a straight line parallel to each other then there exist two cases of relative velocity

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EXPLANATION:

  • As mentioned, two trains A and B are moving with velocity v and they are moving towards each other.

Thus, the relative velocity of train A with respect to train B can be given as:
Vrelative  = |v1 + v2|= v + v = 2v
Hence only option 2 is correct among all.

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