A solid cylindrical disk has a radius of $0.15 \mathrm{m}$. It is mounted to an axle that is perpendicular to the circular end of the disk at its center. When a $45-N$ force is applied tangentially to the disk, perpendicular to the radius, the disk acquires an angular acceleration of $120 \mathrm{rad} / \mathrm{s}^{2} .$ What is the mass of the disk?