A uniform disk of mass M=12.0 kg and radius R=.75 m is free to rotate about a fr

Question

A uniform disk of mass M=12.0 kg and radius R=.75 m is free to rotate about a frictionless axle through its center. A cord is wrapped around the rim of the disk and is pulled with a stead tension of T=100N. As the cord is unwound, the disk rotates and we assume that there is no slippage between the cord and the rim of the disk. I the disk starts from rest, find the (a) the angular acceleration (b) angular velocity (c) the tangential velocity of the disk (d) the angle turned after 6.0s, and (e) the roational kinetic energy.

Explanation / Answer

I= 1/2 Mr^2 = 3.375

torque= T.r = 75 Nm

so angular acceleration = torque /I= 22.22 rad/sec^2

angular velocity after 6 sec = 22.22*6=133.33 rad/sec

tangential velocity=angular velocity *r=100 m/sec

rotational KE= 1/2 I *angular velocity ^2= 30 kJ

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.