Ch6 Work, Enegry and Power notes
PDF IS AVAILABLE IN THE END OF THIS NOTES
Work :-
• When a body moves through a certain distance in any direction under the influence of an applied force except the direction perpendicular to the direction of a platform force .
• It is scalar quantity and scalar or dot product .
 |
| Work done |
Work done in component form :-
 |
| Workdone in component form |
Work done for constant and variable forces :-
 |
| Workdone by constant and variable forces |
# Work Enegry theorem for constant force :-
 |
| Work Enegry theorem |
# Work Enegry theorem for variable force :-
 |
| Work Enegry theorem |
Power :-
Time rate at which work is done or rate of doing work is known as power .
 |
| Power |
Enegry :-
Capacity or ability to do work by a body .
Unit:- Joule
=> Kinetic energy :-
• It is the enegry which possessed with motion .
• Non - Conservative force
 |
| Kinetic Enegry |
# Relation between Kinetic energy and Linear momentum :-
 |
| Relation b/w Kinetic energy and momentum |
=> Potential Energy :-
• It is the enegry which is possessed with position .
• Conservative Force
=> Two important types of potential energy :-
1. Gravitational Potential Energy :-
It is the energy possessed by the body of its position above the surface of the earth .
 |
| Potential Energy |
2. Elastic Potential Energy :-
 |
| Elastic Potential Energy |
Note:-
• Spring of greater force constant 'k' said to be 'stiffer' .
• spring of smaller force constant 'k' said to be 'soft' .
# Spring potential Energy, Work Enegry theorem :-
 |
| Spring potential Energy |
 |
| Workdone by spring force |
Concept of conservative and non conservative :-
=> Conservative Force :-
A force is conservative when workdone bh the net force on a moving particle between the particles initial and final position.
Examples :- • Gravitational force
• Spring Force
• Potential Energy
=> Non Conservative :-
A force is non conservative when the work done by this is dependent on the path being follow the particle are called non conservative force .
Examples :- • Force of friction
• Kinetic energy
Mechanical energy :-
The mechanical energy of a body is the sum of kinetic energy and potential energy .
 |
| Mechanical energy |
# Illustration of law of conservation of mechanical energy :-
 |
| Conservation of Mechanical energy |
Collisions :-
1. Elastic collision :-
• A collision in which there is no loss of kinetic energy is called elastic collision .
• kinetic energy is conserved
• Linear momentum
• Total energy is conserved
• The force must be conservative force .
• Practically, there won't be no perfect elastic collision.
2. Inelastic collision :-
•A collision in which there is same loss of kinetic energy is called in elastic collision .
• Linear momentum is conserved .
• Kinetic energy is not conserved .
• Total energy is not conserved .
• Force must not be conservative .
• Practically there won't be no perfect inelastic .
Elastic Collision in 1-D ( dimension)
 |
| Elastic Collision in 1D |
Inelastic Collison in 1-D(dimension)
 |
| Inelastic Collison in 1D |
 |
| Kinetic energy is not conserved in inelastic Collison |
Elastic Collision in 2-D(dimension)
 |
| Elastic Collision in 2D |
Click here Notes for pdf
