Engineeringmechanics ppt(1)
- 4. Magnitude Direction Point of application Nature
- 6. Resolution of force The process of replacing a single force into number of components, without changing its effect on the body is called Resolution of force
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- 10. Method of approach to solve CONCURRENT and NON CONCURRENT FORCE Systems Problem 2-D Concurrent NotEquilibrium (Resultant) 1.ParallelogramLaw 2. Trianglelaw 3. Polygonlaw 4.Methodof projections Equilibrium (Unknowns) Fx=0 Fy=0 Non-concurrent NotEquilibrium (Resultant) 1.Choose a reference Point 2.Shift all the forces to apoint 3.Find the resultant force and couple at thatpoint 4.Reduce the force- couple system to a single force Equilibrium (Unknowns) ΣFx=0 ΣFy=0 ΣMz=0 3-D Concurrent Notequilibrium (Resultant) --- --- --- -- R = F1+F2+F3 Equilibrium (Unknowns) --- --- R = 0 --- --- -- -- F1+F2+F3,,= 0 ΣFx=0 ΣFy=0 ΣFz=0, NonConcurrent NotEquilibrium (Resultant) --- -- -- -- R=F1+F2+F3…. --- --- --- --- M = M1+M2+M3.... --- --- OPͯr R =M Equilibrium (Unknowns) --- --- R = 0 --- --- M = 0 10 ΣFx=0 , ΣMx=0 ΣFy=0, ΣMy=0 ΣFz=0, ΣMz=0
- 11. Method of approach to solve Coplanar (2D) problems Problem 2-D Concurrent NotEquilibrium (Resultant) 1. ParallelogramLaw 2. Trianglelaw 3. Polygon law 4. Method ofprojections Equilibrium (Unknowns) F =0x Fy=0 Non-concurrent NotEquilibrium (Resultant) 1.Choose a referencePoint 2. Shift all the forces to apoint 3.Find the resultant forceand couple at that point 4.Reduce theforce-couple system to a singleforce Equilibrium (Unknowns) ΣFx=0 ΣFy=0 ΣMz=0 11
- 12. Laws of mechanics Newton’s first law of motion Newton’s second law of motion Newton’s third law of motion Newton’s law of gravitation Laws of parallelogram of force
- 15. Determine the resultant of the following figure
- 16. Determine the resultant of the following figure
- 17. Determine the resultant of the following figure Problem – 2D- Concurrent - Resultant 17
- 18. R 199.12 14.32 R 199.6N 5 Force Mag x comp y comp F1 150 150cos30 150Sin30 F2 80 80sin 20 80Cos20 F3 110 0 110 F4 100 100cos15 100sin1 F x 199.1 F y 14.3 2 2 F X FY R Resultant is 199.1N tan 14.3 N 4.1 Direction is 8 Problemsolution
- 19. Determine the resultant of the following figure Problem – 2D- Non Concurrent - Resultant 11
- 20. Moment of force The rotational effect produced by force is known as Moment of force Couple Two non collinear parallel forces of equal magnitude but acting in opposite direction from couple
- 21. FBD FBD is a sketch of the body showing all active and reactive forces that acts on it after removing all supports with consideration of geometrical angles and distance. Lamis theorem If a body is an equilibrium under the action of three forces each force is proportional to the sine of the angle between the other two forces
- 22. Determine the resultant of the following figure
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