Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A student sits on a rotating stool holding two 4.0 kg objects. When his arms are

ID: 1745340 • Letter: A

Question

A student sits on a rotating stool holding two 4.0 kg objects. When his arms are extendedhorizontally, the objects are 1.0 m from the axis of rotation, andhe rotates with an angular speed of 0.75 rad/s. The moment ofinertia of the student plus stool is 3.0kg·m2 and is assumed to beconstant. The student then pulls the objects horizontally to0.50 m from the rotation axis. (a) Find the new angular speed of thestudent.
(b) Find the kinetic energy of the student system before and afterthe objects are pulled in. before and after J. (a) Find the new angular speed of thestudent.
(b) Find the kinetic energy of the student system before and afterthe objects are pulled in. before and after J.

Explanation / Answer

If is the angular velocity then I11=I22 3*0.75=(4*0.52) From this we get new angular velocity. KEbefore=1/2*I112 KEafter=1/2*I222 Hence we get by it. KEafter=1/2*I222