Question

1) A uniform 14 kg cylinder turns on a horizontal axis with a significant amount of friction. The cylinder has a radius of 0.030 m and a thickness of 0.080 m. It is initially at rest. Then a force of 70 N is applied at a 37 angle for 2.0 s, as indicated in the figure, and the cylinder accelerates. After a time of 2.0 s the force is reduced to 24 N, and then the cylinder continues to spin at constant angular speed.

a) Calculate the magnitude of the torque acting on the cylinder due to friction.

b) Calculate the angular velocity of the cylinder after 2.0 s.

c) Calculate the cylinder’s kinetic energy after 2.0 s.

Answer 1

When (a) forea ndnins forque 24N at constnt So eirion F:24N torghe 24x0.03 sin 37 FR Sin 37 O. 433 N-m from Laus New ton 's Second Ta F= 70N. Ta toraue dus ttere 2-3 1.264 70xo.03 sin 3ゴニ 6. 3 x10- 3 2 Lx14x CO.O3) MR 2 I 264-0.433 てa- So, G3 x10 3 rad/s 131.9 +at intial 131.9 kad/s 263. 8 rad/s 131.9 x 2 Kinere G.3x10 26 3.e) 219.3 J