The mass would have centripetal acceleration a given by
a = v ² / R
where
v = tangential speed of the mass
R = length of the string
By Newton's second law, a maximum tension of F = 135 N would apply an acceleration of
135 N = (2.0 kg) a → a = 67.5 m/s²
which requires a tangential speed v of
67.5 m/s² = v ² / (1.10 m) → v = √((67.5 m/s²) (1.10 m)) ≈ 8.62 m/s
