Question

equilibrium exists (doesn't move up or down) 3. For figure 9.39, two uniform rods of weight W are held by frictionless pins at A and B. Assuming! a coefficient of static friction of .4 at point C, determine whether the rod will stay in equilibrium if theta is 50 degrees 4. For figure 9.41, assume a coefficient of static friction of 25 between body A and the incline. Determine the range of values for the mass of body A so that body B (mass 10kg) remains in equilibrium. Fig. 3.39 Fig. 73.41 ightloss are used to connect a 20kg block A to the 10kg block B

Answer 1

equilibrium , pulley conneeted Aus al since the system is in then , from the FBD of to block B, we have. -s since massless and rest, then. But AT 2T = TI - T = 2T IT Umag =) T= T = 49 Newtons Ti= m. g=1089.8 = -98 Newtons Now, the officient of friction b/w wedge and block À O is us= o-25, and from the FBD Of Åwe have If the block ß mass is I th the block A mass low, such that it just fendt is such that it tends to moves up the incline, then to move dough he incline friction arta in downward , I then friction acto N T direction. I up the incline AN mg sina CT magsinusta 1450 mAg cos 45 Tuso fs uma cosul N = mg 10145 .: N=mag cos450 and fs= lls N = ls Magos45) Also, fs t T = mag Gin 45 i. Ta magsinus tts T=MAQ sin 45-fs. 49=mag + Im - 0.25 493 MATG 0:25 vž

2195 mag fatto m a) mex=> can be givenas. s ma 49 xV2 = 4 GX V2 4 melon g = u 9X VZ min 1025x9.8 0.75 -> (MA) min - 5.656 kg: (MA) may - 92.39 981 (MA) max = 9.42 kg. I. Range of masses of block A such that T it stays in equilibrium is 75 656kg m I go 42 kg Ang