A disk of mass 4kg is mounted on a massless rigid rod BC as shown in the diagram. A torque t = is applied to the arm at C. 5e0.5t 0.25m 0.5m Consider three cases: Case-I: The disk is free to rotate about its bearing at B. Case-II: The disk is rigidly attached to its bearing at B. 289 (A) In case-I, the kinetic energy of disk at t = 2 sec is 2 Case-III: The disk is freely rotating about its bearing at B with angular velocity (-10k) rad/sec prior to application of torque. Take : e = 2.7 -J. Z 1156 (B) In case-II, the kinetic energy of disk at t = 2 sec is 9 339 (C) In case-III, the kinetic energy of disk at t = 2 sec is 2 6281 (D) In case-III, the kinetic energy of disk at t = 2 sec is 16 -J. 0.5t T = (5e)N.m C -J.

As a torque activity, your Physics TA sets up the arrangement shown below. m1 m2 A uniform rod of mass m, 251 g and m2 163 g and length L 100.0 cm is attached to the wall with a pin as shown. Cords are attached to the rod at the r, 10.0 cm and r, 90.0 cm mark, passed over pulleys, and masses of 187 g are attached. Your TA asks you to determine the following. (a) The position r, on the rod where you would suspend a mass m, = 200 g in order to balance the rod and keep it horizontal if released from a horizontal position. In addition, for this case, what force (magnitude and direction) does the pin exert on the rod? Use standard angle notation to determine the direction of the force the pin exerts on the rod. Express the direction of the force the pin exerts on the rod as the angle 0-, measured with respect to the positive x-axis (counterclockwise is positive and clockwise is negative). r3 m %| F. N (b) Let's now remove the mass m, and determine the new mass m, you would need to suspend…

(2) A 30° MK = 0.45 Мк G B MA= 1 = 2 ку .8 kg - In the above arrangement of two blocks and card, the blocks start Use PWE to at rest, and the pulleys are frictionless. Find VA (mag and direc) after may assume that the card tension You B has descended by 0.65 m. is constant. You will need to use NSL to relate N₁ to WA E=mAg), NA and you Should show all the steps of this preliminary step also.

h a = 0.9 NA NB On Determine normal forces at A and B. = 3049.74 dA 1855.26 .G You are forced to pull a group of kindergarteners in a cart. You apply a horizontal force of F = 450 N. The cart has a total mass of m = 500 kg with a center of mass at G. Assume the wheels have negligible mass, negligible size (r) and no rolling resistance. d4 = 0.73 m and dg = 1.2 m. You apply the horizontal force at a height y = 0.4 m from the ground. The center of gravity G is located at a height h = 1.2 m from the ground. Determine acceleration of the cart m XN dв X N B y UBC Engineering