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King Fahd University of Petroleum & Minerals. Mechanical Engineering Dynamics ME 201 BY Dr. Meyassar N. Al-Haddad Lecture # 36. Chapter 18 Planar Kinetics of Rigid Bodies: Work and Energy. Kinetic Energy. General. Translation. Rotation. Rotation.
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King Fahd University of Petroleum & Minerals Mechanical Engineering Dynamics ME 201 BY Dr. Meyassar N. Al-Haddad Lecture # 36
General Translation Rotation
Example Total K.E. ? K.E. of the Body of Bike and man ( translational ) K.E of the wheel ( Translational + Rotational ) Total K.E. = 2 Twheel +T B+Man
mB=6 kg mD=10 kg mC=12 kg No slipping Total K.E = ? Example 18-1 Block (Translation) Disk (Rotation) Cylinder ( Translation &Rotation)
Problem wAB=wCD=10 Ib wBC=20 Ib Total K.E = ?
Force That Do No Work • Force Perpendicular to the displacement • Weight • Normal reaction Rolling resistance force Fr Fr acts at point which has zero velocity The point is not displaced
Ox Oy On Ot Pin Reaction Pin Reaction Do No work Act on zero velocity and create no displacement
The Work of a couple -Do work only when the body undergoes a rotation -Translation : positive work cancels the negative work -Rotation
Example 18-2 m =10 kg M = 50 NmP = 80N, unstretched 0.5 m total work ?