Question

Two trains are travelling away from a common station at speeds of u and 2u, in directions that are at an angle 60° to each other. What is the velocity of the train with speed 2u relative to an observer in the other train?

Answer 1

Let the Two trains X and Y are travelling away from a common station at speeds of u and 2u at an angle of 60° respectively.

Now according to question 
let an observer in the other train i.e train Y

By the diagram the components of velocity w.r.t x and y- axis is given as :-

 = 2ucos60°(i^) + 2usin60°(j^)
                           = 2u* 1/2(i^) + 2u* √3/2(j^)
                           =u(i^) + √3u(j^)
                           
 = u(i^)

For  velocity of the train with speed 2u relative to an observer in the other train -
 =  - 
                             = u(i^) + √3u(j^) - u(i^)
                             = √3u(j^)

In magnitude √3u m/s it is the velocity of the train with speed 2u relative to an observer in the other train.

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Best of luck ;)
ROYALJATT

Answer 2

Answer:

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