The spool has a weight of $30 \mathrm{lb}$ and a radius of gyration $k_{o}=0.45 \mathrm{ft}$. A cord is wrapped around its inner hub and the end subjected to a horizontal force $P=5 \mathrm{lb}$. Determine the spool's angular velocity in 4 s starting from rest. Assume the spool rolls without slipping.