A drum rotates around its central axis at an angular velocity of $13\mathrm{.}50$ rad$/$s$.$ Assume that the drum then slows at a

constant rate of $4\mathrm{.}70$ rad$/$s$2.$

$39.$ How much time is required for it to come to rest?

a$.0\mathrm{.}74$ s

b$.0\mathrm{.}35$ s

c$.2\mathrm{.}8$ s

d$.$

$40.$ Through what angle does it rotate as it comes to rest?

a$.19\mathrm{.}3$ rad

b$.56\mathrm{.}22$ rad

c$.2\mathrm{.}87$ rad