The dimensions of various links in a mechanism, as shown in Fig. 6.34, are as
follows : A B = 25 mm ; BC = 175 mm ; CD = 60 mm ; AD = 150 mm ; BE = EC ; and EF = FG
= 100 mm. The crank A B rotates at 200 r.p.m. When the angle BAD is 135°, determine by
instantaneous centre method : 1. Velocity of G, 2. Angular velocity of EF, and 3. Velocity of
sliding of EF in the swivel block S. [Ans. 120 mm/s ; 6.5 rad/s ; 400 mm/s]
AB=25 mm, BC =175 mm, CD =60 mm ; AD =150 mm, BE =EC , EF= FG = 100 mm
"\\omega_{AB}=200 rpm = \\frac{200*2 \\pi}{60}=20.94 rad\/sec"
"V_B=AB *20.94 rad\/sec=25*20.94 = 523.6 mm\/sec"
"\\frac{V_B}{4.5}=\\frac{V_E}{9.6} \\implies \\frac{523.6}{4.5}=\\frac{V_E}{9.6} \\implies V_E=1117.01 mm\/sec"
"\\frac{V_F}{8.9}=\\frac{V_G}{9.6} \\implies \\frac{V_F}{8.9}=\\frac{1117.01}{9.6} \\implies V_F=1035.56mm\/sec"
"V_G=\\frac{V_F*I_1G}{I_2F}=\\frac{1035.56*4.2}{8.9}=486.691 mm\/sec"
"v=r \\omega \\implies \\omega _{EF}=\\frac{V_E}{EF}=\\frac{1117.01}{100}=11.170 rad\/sec"
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