RADIATION

PAGE Unit1:Chaptor1: Page | 3

Engineering MechanicsBy Dr.Manu Gupta

Contents of the Subject.

Unit 1

1. Static Of Particles and Rigid Bodies: Fundamental laws of mechanics, Principle of transmissibility, System of forces, Resultant force, Resolution of force,

2. Moment and Couples, Varignon's Theorem, Resolution of a force into a force and a couple, Free body diagram, Equilibrium, Conditions for equilibrium, Lami's theorem.

3. Virtual work: Principle of Virtual Work, Active forces and active force diagram.

Unit 2

4. Centroid & Moment of Inertia: Location of centroid and center of gravity, Moment of inertia, Parallel axis and perpendicular axis theorem, Radius of gyration, M.I of composite section, Polar moment of inertia, M.I of solid bodies.

5. Lifting Machines: Mechanical advantage, Velocity Ratio, Efficiency of machine, Ideal machine, Ideal effort and ideal load, Reversibility of machine, Law of machine, Lifting machines; System of Pulleys, Simple wheel and axle, Wheel and differential axle, Westons differential pulley block, Worm and worm wheel, Single purchase winch crab.

Unit 3

6. Friction: Types of Friction, Laws of friction, Angle of friction, Angle of repose, Ladder, Wedge, Belt Friction.

7. Belt Drive: Types of belts, Types of belt drives, Velocity ratio, Effect of slip on Velocity ratio, Length of belt, Ratio of tensions and power transmission by flat belt drives.

1. Fundamental of mechanics1. Definition

Mechanics is the branch of physics deals with the behavior of bodies at rest or in motion, when subjected to forces or displacements and effect on their environment. Why to use mechanics?

To know mechanics is important to develop machines, and that is what an engineer does. So it is most fundamental subject of engineering. Starting from the analysis of rigid bodies under gravitational force and simple applied forces the mechanics has grown to the analysis of robotics, aircrafts, spacecrafts under dynamic forces, atmospheric forces, temperature forces etc.2. History:

Archimedes (287212 BC), Galileo (15641642), Sir Issac Newton (16421727) and Einstein (18781955) have contributed a lot to the development of mechanics. Contributions by Varignon, Euler, D. Alembert are also substantial. The mechanics developed by these researchers may be grouped as

(i) Classical mechanics/Newtonian mechanics

(ii) Relativistic mechanics

(iii) Quantum mechanics/Wave mechanicsSir Issac Newton, the principal architect of mechanics, consolidated the philosophy and experimental findings developed around the state of rest and state of motion of the bodies and put forth them in the form of three laws of motion as well as the law of gravitation. The mechanics based on these laws is called Classical mechanics or Newtonian mechanics.Albert Einstein proved that Newtonian mechanics fails to explain the behaviour of high speed (speed of light) bodies. He put forth the theory of Relativistic Mechanics.Schrdinger (18871961) and Broglie (18921965) showed that Newtonian mechanics fails to explain the behaviour of particles when atomic distances are concerned. They put forth the theory of Quantum Mechanics.3. Classification Of Engineering Mechanics:

PAGE ARYA. BY Dr. Manu Guptamanukota1@gmail.com