Two Ice Skaters Force On Each Other

[thulling]

1. On an ice rink, two skaters of equal mass grab hands and spin in a mutual circle once every 2.4 s.
If we assume their arms are each 0.75 m long and their individual masses are 56.0 kg, how hard are they pulling on one another? (answer is F= __N)



2. I thought I should use the equation F= G((M one)(M two))/radius squared
where G=6.67*10^-11 N*(m/kg)squared

3. I attempted to plug in the numbers to this equation and got F=3.7*10^-7
This answer was incorrect.

I know I am given time=2.4s, but I am not sure where to use this. ?

Please help

 

[willem2]

That equation you used was for the force of gravity between the skaters. It's not significant here. Try to use F=ma

 

[thulling]

I got it! Thanks so much!