Question

To start her lawn mower, Julie pulls on a cord that is wrapped around a pulley. The pulley has a moment of inertia about its central axis of III = 0.590 kg⋅m2kg⋅m2 and a radius of 4.00 cmcm . There is an equivalent frictional torque impeding her pull of τfτftau_f = 0.260 m⋅Nm⋅N .

To accelerate the pulley at ααalpha = 4.35 rad/s2rad/s2 , how much torque does Julie need to apply to the pulley?

How much tension must the rope exert?

Answer 1

(1) moment of inertia of pully;

I = 0.59 kg.m^2;

radius of pully r = 4 cm = 0.04 m;

frictional torque;

angular acceleration of pully;

(a) Torque applied to the pulley

;(b)

where T is the tension in the string;