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circular tract.. doubt

circular tract.. doubt

by Sinjan Jana -
Number of replies: 1

Two runners start simultaneously from the same point on a
circular 200-m track and run in same directions. One runs at a
constant speed of 6.20 m/s, and the other runs at a constant speed
of 5.50 m/s.

when will the fast one overtake the slower one?

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this may be an easy problem, but I am getting confused... as far as I have analyzed.. the distance traveled for overtaking is same and the time taken for overtaking is different....

If this is the correct analysis.. then I am not able to proceed further... can yiu help me to proceed??

Thanxx..!!!
In reply to Sinjan Jana

Re: circular track.. doubt

by Manish Verma -

The faster one is going to travel more distance. Time is going to be the same.

Method I

Let us say the faster one completes n full revolutions + x distance and the slower one completes m full revolutions + x distance. Then, we have:

\(\frac {2\pi r.n+x}{6.20}=\frac {2\pi r.m+x}{5.50}\)

Where n and m are the number of turns which should be minimum for x < 200. x is the extra distance after full revolutions.

Method II

Let the slower one be the reference frame. The faster one will take a few additional full revolutions with respect to the slower one.

\(0.7=\frac {2\pi r.n}{t}\)

n is the smallest natural number.