Question

Q2. Consider the mild steel engine connecting rod length 20cm and thickness 1cm shown in Figure Q2a. At an instant during use, the connecting rod has an angular velocity of magnitude 30rad/s and an angular acceleration of magnitude 500rad/s2. Figure Q2a a) Use clearly stated assumptions (it is acceptable to treat the connecting rod as box shaped) to first roughly estimate the following: i. ii. iii. Overall mass. location of the mass centre (state also how you could find this in practice). mass moment of inertia about an axis through the mass centre and perpendicular to the plane of motion of the connecting rod. the angular momentum of the connecting rod about an axis through the mass centre and perpendicular to the plane of motion of the connecting rod. the inertial moment resisting the angular acceleration. iv. V. [15 marks]

Answer 1

of mild steel 7.85x10 kg/m3 Density Given to anume box shaped d=201m, t=1cm Volume . Overall man = density Volume = ext² = 20x1²= 20 cm3 3 Overall man = 7-85x20x108 DIO = 0.157 kg Normally connecting and is asused to be - haviy two point man at two ends in to form dynamically Gervalente mg I mrm- mg; mbe Ma Om Ia mb²+ Ma² m 20 man Centre will be at helf of length for box-shaped Connecting ood. C 0.1577 (0.2² 5.93 X10" Rg-m² I = mi 12 Lz IW = 5:23X16 "x 30 = 0 156.9x16" 4 Femmed Inential moment desting & is meid m= I1 = 5.23x10 4500=0.2615 Nom