A horizontal disk of moment of inertia 4.25 kg-m^{2} with respect to its axis of symmetry is spinning counter clockwise at 15 revolutions per second about its axis, as viewed from above. A second disk of moment of inertia 1.80 kg-m^{2} with respect to its axis of symmetry is spinning clockwise at 25 revolutions per second as viewed from above about the same axis and is dropped on top of the first disk. The two disks stick together and rotate as one about their axis of symmetry. The new angular velocity of the system as viewed from above is close to -

Question

A horizontal disk of moment of inertia 4.25 kg-m^{2}  with respect to its axis of symmetry is spinning counter clockwise at 15 revolutions per second about its axis, as  viewed from above. A second disk of moment of inertia 1.80 kg-m^{2}  with respect to its axis of symmetry is spinning clockwise at  25 revolutions per second as viewed from above about the same axis and is dropped on  top of the first disk. The two disks stick together and rotate as one about their axis of symmetry. The new  angular velocity of the system as viewed from above is close to -

Examsnet · Accepted Answer

Correct Answer is :  3 revolutions/second and counter clockwise

KVPY SX SB Exam 2015 Question Paper