There is a mass at the end of a 0.6 m string, being swung around overhead at constant acceleration of(3/4)pi rad/sec^2. mass is 39.84 G. Tensile strength is 12.4 newtons

need to find how many revolutions there will be before the string breaks, and the time before that happens. What equations do I need?

T=F=mv²/R=mω²R

ω=sqrt(T/mR)
ω = εt
t=ω / ε
2πN= εt²/2
N= εt²/4π