$8.(10\mathrm{.}8)$ A uniform disk with mass $40\mathrm{.}1$ kg and radius $0\mathrm{.}260$ m is pivoted at its center about a horizontal, frictionless axle that is stationary. The disk is initially at rest, and then a constant force $30\mathrm{.}5$ N is applied tangent to the rim of the disk.

a$.$ What is the magnitude $\backslash ($ v $\backslash )$ of the tangential velocity of a point on the rim of the disk after the disk has turned through $0\mathrm{.}260$ revolution? $\backslash (1\mathrm{.}14\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash )$

b$.$ What is the magnitude a of the resultant acceleration of a point on the rim of the disk after the disk has turned through $0\mathrm{.}260$ revolution? $\backslash (5\mathrm{.}20\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}2\backslash )$