Question

Problem 19.25 ( 13 of 14 Review The 45-lb flywheel A has a radius of gyration about its center of 4 in. Disk B weighs 70 lb and is coupled to the flywheel by means of a belt which does not slip at its contacting surfaces. A motor supplies a counterclockwise torque to the flywheel of M = (50t) lb. ft, where t is in seconds. (Figure 1) Part A Figure Determine the time required for the disk to attain an angular velocity of 70 rad/s starting from rest. Express your answer to three significant figures and include the appropriate units. < 1 of 1 > ? Å Value O Units M = (501) lb. ft t= 6 in. Submit Request Answer Provide Feedback Next >

Answer 1

Masolboft 19:23 Geren Data The 45-16' Plywheel A has a radius of gyration about Pts centre of 4in. DESIB Weights Toeb' And is Coupled to the fly wheel by means of a belt which does not slip at Bts Contalling surfacess A motor supplies a counter Clockwise torque to the Fly wheel of m=150&tb.ft. part A: We have to Determines the time required for the disk to attain an angulal velocity of 70 radi see Starting from rest. Angular momentum about a IA(WA) & ESMA dt = IA(WA) 20+ JEM- (T, -12) NA ]dt = Walo KA (WA) Mdt - 0.53% c-12) dt = 0.155 (was → © Angular momentum about B, Ib (WB), + Efmß dt Id (WR)a 0+ $*(+,-1a) wg dt = WB) g x (WB). 945*CT-Ta) dt = 192., *(Y9" cwe)s 0.015 (We) = $ (1,-Taldt > Mp 3 A WA = 0.SWA Me z MBMB = (3/4) WR = 0.7 WB i Belt moves without supping & Np =va WA), = 15WB),t>© from @ & 0 Smat - 05 [0.815 (WB)2] a 50 (4/2) = 0.641 (LOB) +”= 1282(10) - tel.339 sec