Question

A drum rotates around its central axis at an angular velocity of 10.4 rad/s. If the drum then slows at a constant rate of 5.55 rad/s2, (a) how much time does it take and (b) through what angle does it rotate in coming to rest

Answer 1

Answer:

t=1.87s

b. 9.74

Explanation:

First to find time set an equation for angular velocity:

$w_{2}=w_{1}+\alpha t\\0=10.4-5.55t\\-10.4=-5.55t\\1.87=t$

Now to find the angle:

$x=x+wt+\frac{\alpha}{2} t^2\\x=10.4*1.87-\frac{5.55}{2} 1.87^2\\x=9.74$