Agirl is running toward the front of a train at 10 m/s. if the train is going 75 m/s on the southbound tracks, what is the speed of the train relative to the girl?

velocity of the train with respect to girl is 85 m/s

Explanation:

As we know that girl is moving towards the train in front of it with speed

also we know that the speed of the train towards the girl is

Now we know that relative velocity of the train with respect to girl is given as

here let say the velocity of train is positive while girl is running opposite to train so its velocity is negative

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

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