A 700g block on a 130.0 cm long string (radius) swings in a circle on a horizontal frictionless surface. If the string will break when the tension exceeds 36.0 N, at what maximum rpm can the block rotate?
It will break when
M*R*w^2 = 36.0 N
Use M = 0.70 kg
R = 1.30 m
and solve for the angular velocity w, in radians per second.
Then convert w in rad/s to revolutions per minute
1 rad/s = 60/(2 pi) = 9.55 rpm