Answer
$121^{\circ}$
Work Step by Step
We know that
$sin\theta=(\frac{\omega_f}{rmv})(1+mr^2)$
We plug in the known values to obtain:
$sin\theta=\frac{0.272rad/s}{(2.31m)(34.0Kg)(2.80m/s)}[512Kg.m^2+(34.0Kg)(2.31m)^2]$
$\implies sin\theta=0.8576$
$\implies \theta=59.05^{\circ}$
Now $\theta=\pi -59.05^{\circ}$
$\theta=180^{\circ}-59.05^{\circ}=121^{\circ}$