A mass of 80g is moving in a horizontal circle supported by a string 1.2m long suspended from a fixed point in the centre of the circle. The mass completes each revolution in 0.85s. Calculate the tension in the string. Relevant equations: I'm not entirely sure, but these were the ones I was considering: T = 2∏R/v F = mg ω = 2∏ / T 3. The attempt at a solution I think that I need to find the angle between the string and the horizontal, but I don't know how to do that. I've got the hypotenuse of the triangle which is 1.2m.. I also calculated ω using the above equation and got 7.39rad/s. But now I'm lost. Help?