A49.0 kg wheel, essentially a thin hoop with radius 0.730 m, is rotating at 114 rev/min. it must be brought to a stop in 22.0 s. (a) how much work must be done to stop it? (b) what is the required average power? give absolute values for both parts.

Explanation:

Mass of the wheel, m = 49 kg

Radius of the hoop, r = 0.73 m

Initial angular speed of the wheel,

Final angular speed of the wheel,

Time, t = 22 s

(a) If I is the moment of inertia of the hoop. It is equal to,

We know that the work done is equal to change in kinetic energy.

W = -1858.05 Joules

(b) Let P is the average power. It is given by :

P =84.45 watts

Hence, this is the required solution.

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer