Centripetal force experiment help

[kisha]

i am confused.i need help with this experiment.

experiment set up:
http://img155.imageshack.us/img155/4027/20120428151358.png

1.measure total mass M of the crocodile clip and load.(in gram)
2.measure a length L of the string from the glass tube.
3.hold the tube vertically and whirl the rubber bung around.
4.measure the time t required for the bung to complete 50 revolutions.
5.repeat step 2-3 using different L.
6.plot t^2 against L.
7.prove [PLAIN]http://img577.imageshack.us/img577/7543/20120428153604.png

how to prove[PLAIN]http://img577.imageshack.us/img577/7543/20120428153604.png by using Mg=mLω^2 and ω=2∏/T(period)?

 

[K^2]

Solve your equations for t(L). What is the slope of f(L)=t²(L)?

 

[kisha]

slope=t²/L

 

[K^2]

Well, yeah, but what's t²?