Answer:W = -5.808J
Explanation:
Given:
Mass of hoop,m=120kg
Centre of mass speed of hoop,v= 0.220m/s
Rotational inertia,I= mr^2
I=120r^2
Kinetic energy of hoop= Linear kinetic energy + Rotational kinetic energy
K= (1/2mv^2) + (1/2Iw^2)
But w= (v/r)^2
K= (1/2mv^2) + (1/2×120r^2(v/r)^2)
K = (1/2×120×0.220^2) + (1/2×120×0.220^2)
K= 5.808J
To stop the hoop,its final kinetic energy must be zero,
Workdone = Kfinal-Kinitial = 0 - 5.808
W= -5.808J
