What is the angular momentum of a 0.210kg ball rotating on the end of thin string in a circle of radius 1.10m at angular speed of 10.4 rad/s?

I got 2.64 kgm²/s.

L = r * p = r * mv

r= 1.1m
m=0.210kg

v=distance/time

We know the rate of revolution (10.4 rad/s = 10.4/(2 * Pi) revs/s)
We know the radius of the circle, and thus the circumference which is 2.2*Pi m/rev.

So, the velocity is (10.4/(2 * Pi) revs/s) * 2.2*Pi m/rev = 11.44 m/s

Ending with:

L = (1.10m) * (0.210kg) * (11.44 m/s) = 2.64 kgm/s²
Physics is not my area of expertise, but I think that should be correct.