A motor drives a cylinder of radius 0.308 m and moment of inertia 3.4 kg·m2. A massless rope is wrapped around the cylinder with a bucket of mass 10.48 kg tied to the free end of the rope. The motor raises the bucket with constant acceleration 0.39 m/s2
1)Find the magnitude of the torque exerted by the rope on the cylinder
2)Find magnitude of the torque delivered by the motor

Question

A motor drives a cylinder of radius 0.308 m and moment of inertia 3.4 kg·m2. A massless rope is wrapped around the cylinder with a bucket of mass 10.48 kg tied to the free end of the rope. The motor raises the bucket with constant acceleration 0.39 m/s2 
1)Find the magnitude of the torque exerted by the rope on the cylinder
2)Find magnitude of the torque delivered by the motor

irishboy123 · Answer

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for the first part, calculate F in the drawing and use F x radius to calculate the torque on the cylinder.

for the second part Torque = that torque you just calculated PLUS I alpha where I = mom of inertia of cylinder and alpha is its angular acceleration.  relate that to the bucket's cceleration via the cylinder's radius.

any problems with any of this, just ask.  cheers.