If the ball revolves twice every second, what is the tension in the string?

[Alexs45]

A 0.25-kg ball attached to a string is rotating in a horizontal circle of radius 0.5 m. If the ball revolves twice every second, what is the tension in the string?

 

[arildno]

1) How can you figure out the velocity of the ball by the information given?
2) How is that velocity related to the centripetal acceleration experienced by the ball?
3) How is the centripetal acceleration of the ball related to the tension in the string?

 

[p53ud0 dr34m5]

$$v = \frac{2 \pi r}{T}$$
$$a_c = \frac{v^2}{r^2}=\frac{4 \pi^2 r}{T^2}$$
$$m \cdot a_c = F_T + F_g$$
i don't know if that's it, because I am kind of limited on my sources. I am at work, and I am not even supposed to be on this site. the last equation is probably wrong, but i know the first two are right. well, i think.

 

[Alexs45]

i don't think that is right, i need the step by step help

 

[p53ud0 dr34m5]

all you have to do is plug in the numbers.