I can't figure out how to start this.

"A small block with mass 0.170 kg is attached to a string passing through a hole in a frictionless, horizontal surface. The block is originally revolving in a circle with a radius of 0.800 m about the hole with a tangential speed of 4.00 m/s. The string is then pulled slowly from below, shortening the radius of the circle in which the block revolves. The breaking strength of the string is 30.0 N. What is the radius of the circle when the string breaks?"

4 answers

a = v^2/r
F = ma
Ah, yes but remember that angular momentum is conserved to get v as a function of r
m r v = constant
ANANIZI SİKEYİM
BENDE SENİN ANNENİ SİKTİM