Chapter 1 Vector Mechanics Statics Mechanical Engineer.pptx

Chapter 1 of Vector Mechanics

1. ME 245 Engineering Mechanics I Contact Hours: 3.00 Credit Hours: 3.00

2. Objective 1. Introduction to the construction of “Free Body Diagrams” of real-world problems and apply Newton’s Laws of motion and vector operations to assess equilibrium of particles and bodies 2. To apply the principles of equilibrium of particles and bodies to analyze the forces in planar truss members and structures. 3. Understanding the theory of dry friction and analysing the equilibrium of rigid bodies subjected to this force 4. To discuss the concepts of center of gravity, centroids and moment of inertia and apply the concepts to compute their location for bodies of arbitrary shape

3. Topics to be covered Basic concepts of mechanics: Free body diagrams; S tatics of particles and rigid bodies; Properties of forces: Concurrent / coplanar / non-coplanar force systems, resultant of forces, resolution of forces, rectangular and polar components of forces in plane and 3-D space; Analysis of structures: Forces in trusses, frames and machines, zero force members; F orces in cables; F riction; Equilibrium of rigid bodies: Conditions for maintaining equilibrium in 2-D and 3-D; Statical determinacy: Identification of known forces and solution of unknown reactions for a structure, combined loads, application of equilibrium equations for statical determinacy; Moments of inertia: Of areas and masses; moments of force in vector notation; E quivalent force system;

4. LEARNING OUTCOMES & GENERIC SKILLS No. Course Outcomes Corresponding PO Bloom’s Taxonomy KP CP CA Assessment Methods CO1 Determine the equilibrium of a particle and rigid bodies in space using principle of laws of mechanics 1,2 C1, C2, C3 1,2,3     Q, ASG, F CO2 Understanding of force systems of planar truss member, structures 1,2 C2, C3 1,2,3     Q, ASG, F CO3 Analyse and design systems that include frictional forces 2,3 C2, C3, C4 1,2,3,4 1,2   Q, F, CS CO4 Determine location of center of gravity, centroids and moment of inertia of bodies of arbitrary shape. 1,2 C2, C3 1,2,3 1,2   Q, F, CS   (CP- Complex Problems, CA-Complex Activities, KP-Knowledge Profile, T – Test ; PR – Project ; Q – Quiz; ASG – Assignment; Pr – Presentation; R - Report; CS – Case study, F – Final Exam)  

5. TEACHING LEARNING STRATEGY Teaching and Learning Activities Engagement (hours) Face-to-Face Learning  42 Self-Directed Learning 75 Formal Assessment 5.5 Total 122.5 TEACHING METHODOLOGY Class Lecture, Pop quiz, Case study, Problem solving

6. REFERENCE BOOKS Vector Mechanics for Engineers: Statics– Ferdinand P. Beer, E Russell Johnston, Jr; Publisher – McGraw-Hill Companies, 11 th edition 1988. 2. Engineering Mechanics Statics (12 th Edition)– R.C. Hibbeler

7. Mechanics Mechanics is a branch of the physical sciences that is concerned with the state of rest or motion of bodies that are subjected to the action of forces.

8. Mechanics Rigid Body Mechanics Statics Dynamics Deformable Body Mechanics Fluid Mechanics

9. Fundamental Concepts Particle: A particle has a mass, but a size that can be neglected. When a body is idealized as a particle, the principles of mechanics reduce to a rather simplified form since the geometry of the body will not be involved in the analysis of the problem. Rigid Body: A rigid body can be considered as a combination of a large number of particles in which all the particles remain at a fixed distance from one another, both before and after applying a load. In most cases the actual deformations occurring in structures, machines, mechanisms, and the like are relatively small, and the rigid-body assumption is suitable for analysis. Concentrated Force: A concentrated force represents the effect of a loading which is assumed to act at a point on a body. We can represent a load by a concentrated force, provided the area over which the load is applied is very small compared to the overall size of the body.

10. Newton’s Three Laws of Motion First Law: A particle originally at rest, or moving in a straight line with constant velocity, tends to remain in this state provided the particle is not subjected to an unbalanced force. Second Law: A particle acted upon by an unbalanced force F experiences an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force. If F is applied to a particle of mass m, this law may be expressed mathematically as Third Law: The mutual forces of action and reaction between two particles are equal, opposite, and collinear.  

11. Newton’s Law of Gravitational Attraction Shortly after formulating his three laws of motion, Newton postulated a law governing the gravitational attraction between any two particles. Stated mathematically Weight: According to Equation, any two particles or bodies have a mutual attractive (gravitational) force acting between them. In the case of a particle located at or near the surface of the earth, however, the only gravitational force having any sizable magnitude is that between the earth and the particle. Consequently, this force, termed the weight , will be the only gravitational force considered in our study of mechanics. let, By comparison with , we can see that g is the acceleration due to gravity. Since it depends on r , then the weight of a body is not an absolute quantity. Instead, it’s magnitude is determined from where the measurement was made. For most engineering calculations, however , g is determined at sea level and at a latitude of 45°,which is considered the “standard location.”  

12. Homework Systems of Units Conversion of Units Prefixes