Question

A potter's wheel having a radius 0.53 m and a moment of inertia 12.1 kg m is rotating freely at si rev/min. The potter can stop the wheel 25 dy pressing weragaan a radially inward force of 71 N. Find the effective coeficient of kinetic friction between the wheel and the wet rag anderer Need Help? Read Teo Tutor

Answer 1

here,

the radius of wheel , r = 0.53 m

the moment of inertia , I = 12.1 kg.m^2

initial angular velocity , w0 = 51 rev/min = 5.338 rad/s

time taken , t = 7.5 s

using first equation of motion

w = w0 + alpha * t

0 = 5.338 + alpha * 7.5

alpha = 0.71 rad/s^2

retarding force , Fr = 71 N

let the coefficient of kinetic friction be uk

using second equation of motion

I * alpha = r * ( uk * Fr)

12.1 * 0.71 = 0.53 * uk * 71

solving for uk

uk = 0.242

the coefficient of kinetic friction is 0.242