1. Jan 7, 2010

Instanbul

1. The problem statement, all variables and given/known data
How much force is needed to swing a 4kg mass in a 3m radius horizontal circle so that each cycle takes exactly 2 seconds. Answer is 118N but the problem is how do I get to that...

2. Relevant equations
V=2Pir/T F=mv^2/r

3. The attempt at a solution
I tried using F=mv^/r one but I got nowhere close my teacher just solves problems without explaining at all and I have no clue how to solve it except find numbers.

2. Jan 7, 2010

rock.freak667

I one cycle takes 2 seconds, how many cycles are in one second? Hence what is the angular velocity of the bat?

3. Jan 7, 2010

Instanbul

It doesn't say thats all the info that the problem gives me.

4. Jan 7, 2010

rock.freak667

I am quite sure you can find the the number of cycles in 1 second given, that 1 cycle takes 2 seconds.

5. Jan 7, 2010

Instanbul

Aren't I looking for the force of the swing?

Last edited: Jan 7, 2010
6. Jan 7, 2010

rock.freak667

Yes but you need to get the periodic time to get F.

7. Jan 7, 2010

Instanbul

Oh I get it now thank you so much.