# Circular Motion probem 2

1. Sep 4, 2013

Hi friend the problem is as follows:

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Attempt:

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Please friends help me in this.

Last edited by a moderator: May 6, 2017
2. Sep 4, 2013

### Tanya Sharma

Instead of using a=dv/dt use a=vdv/ds.

The given condition is |aT|=|aN|

i.e -vdv/ds=v2/R .

Integrate with proper limits and you will get the answer.

3. Sep 4, 2013

Thank you very much tanya. I got the answer.

But Was I doing it in wrong manner?

4. Sep 4, 2013

5. Sep 4, 2013

6. Sep 4, 2013

7. Sep 4, 2013

### ehild

The particle was decelerating, so your first equation should have been a=-v2/R. The other error was, that when you integrated v with respect time, you forgot the lower limit of integration. So your result is dimensionally incorrect. Tanya's solution is very elegant and simple, but yours is also all right if you do it properly.

ehild

8. Sep 4, 2013

The lower limit of time should be zero. The question states that.

9. Sep 4, 2013

### ehild

Yes, but you have ln(R-vot), it is not zero at t=0.

10. Sep 4, 2013

### Tanya Sharma

After integration when you put t=0,the term doesn't vanish.You have erroneously assumed it to be 0.

11. Sep 4, 2013