Fig. shows a uniform disc of mass 1 kg and radius 0.2 m mounted on an axle supported in fixed frictionless bearings. A light string is wrapped around the rim of the wheel. A constant downwards pull of 2 kg wt. is exerted on the string. What is the angular acceleration of the wheel and the tangential acceleration of a point on the rim ?

Answer

`196 m//s^(2), 39.2 m//s^(2)`

Explanation

T-tangential force, `Tr=lalpha = (1//2) mr^(2)alpha, alpha =2T//mr = 2 xx 19.6//1 xx 0.2 = 19.6 "rad/s"^(2), a =ralpha = 0.2 xx 19.6 = 39.2 m//s^(2)`