Question

8. In the engine system shown 1= 150 mm and b = 50 mm. The crank AB rotates with a constant angular velocity of 100 rad/s in the clockwise direction. Use motion analysis to answer the following when 0=30°: i) Show the coordinate system for the motion analysis ii) Find the velocity of point B iii) Find the angular velocity of connecting rod BD iv) Find the velocity of point D (30 points) P D B А

Answer 1

B 10orad's o To draw Coordinate system, we will take lo dows rest. it is at A as reference since Velocity of point B = bx WAB 50 x 100 mm os VB 5000 mm ک WODOC let

B 30 60 VB rool Coordinate System ത്ത 9 2 26 J x d 1 5000 mm/s E a hoy to be 68 DV B VB = 5000 mm Is Vertical Velocity of D will be in perpendicular direction (it will be be downwards) also DB should meet By considering these two criteria , we can complete the triangle To B From figure pol = nol AD = AB Cosco S = 5000 mm x cos(60) = 2500 mm/s

Velocity of Is D = 2500 mm 2500 mm mm/s AB singo NO ally, DB = = 5000 sinto 4330,127 mm/s w.dit D = 4330.127 so velocity of point B mm Ls le, WB D X L BD = 4330.127 mm/s WBD 4330.127 130 was = 28.37 vadis