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.

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.