A simple angular velocity with two spheres problem

1. Dec 10, 2016

dennislam

1. The problem statement, all variables and given/known data
Two masses have same mass m, both of them are tied by a string and put in a hollow cylinder.
When the cylinder start to rotate until the angular speed is ω.
The tension in the string is T and the string breaks, both masses move away from the axis in the hollow cylinder.

2. Relevant equations
T=mrω^2

3. The attempt at a solution
I have no idea about whether the tension T is equal to mrω^2 or 2mrω^2 (since there is two masses)

2. Dec 10, 2016

BvU

If you pull a spring with a force F, the spring pulls back with a force F. The tension in the spring is F, not 2F.
Same with a rope. In the situation described, but e.g. also if the rope hangs over a pulley and the two masses both pull down with $mg$. Tension is $mg$, not $2mg$