A 0.25 kg ball on a string moves in a horizontal circle of radius 0.60 m at 1.5 revolutions per…

Step 1. (a) $\omega = 2\pi \times 1.5\ \text{Hz} = 9.42\ \text{rad/s}$, $v = 9.42\ \text{rad/s} \times 0.60\ \text{m} = 5.65\ \text{m/s}$, so $L = 0.25\ \text{kg} \times 5.65\ \text{m/s} \times 0.60\ \text{m} = 0.848\ \text{kg m}^2/\text{s}$.

Step 2. (b) $r_\perp = 3.0\ \text{m}$: $L = 2.0\ \text{kg} \times 5.0\ \text{m/s} \times 3.0\ \text{m} = 30\ \text{kg m}^2/\text{s}$. It stays the same, since nothing acts on the particle.