試題詳解

35. A 10 N tangential force is applied at the edge of a 20 kg disk with a radius of 2.0 m. Then, the disk rotates from rest. What is the kinetic energy of the disk 3.0 s after the force is applied?
(A) 180 J
(B) 360 J
(C) 45 J
(D) 90 J
(E) 23 J