A 3.21 kg mass attached to a light string

Question

rotates on a horizontal, frictionless table. The
radius of the circle is 0.855 m, and the string
can support a mass of 15.3 kg before breaking.
What maximum speed can the mass have
before the string breaks?
Answer in units of m/s

Answer 1

m₁=3.21 kg
m₂=15.3 kg
m₂g=T
m₁v²/R=T
m₁v²/R= m₂g
v=sqrt{ m₂gR/ m₁}=
=sqrt{15.3•9.8•0.855/3.21} = 1.8 m/s

Answer 2

6.32 m/s