Energy:
It is
defined as the capacity to do work.
Ex: A system
does some work, when it possess energy.
The Energy
Possessed by the system is of 2 types.
- Stored energy &
- Transit energy
1. Stored Energy: The energy possessed by the system within the boundaries.
Ex: Potential energy, Kinetic energy and Internal energy
2. Transit Energy: The energy possessed by the system which is capable of crossing
the boundaries.
Ex: Heat, Work, Electrical energy etc.,
Types of
Stored Energy
Potential Energy: The energy possessed by the body, to do
some work by virtue of its position
above the ground level.
Ex: a body
raised to some heigh above the ground level possess potential energy.
Because it does some work when it
falls on the ground.
PE=mgh Units=N-m
PE=
Potential energy
m = mass of
the body
h = height
of the body through which it falls.
Kinetic Energy: The energy possessed by the body, to do some work by virtue of
its motion(because of mass and velocity).
KE= Kinetic
energy
m= mass of the
body
V= Velocity of
the body
Internal
Energy:
The energy possessed by the body, due to molecular arrangement and motion of
molecules within the system is called internal Energy.
It is denoted by “U”
Total Energy
E=PE+KE+U
It the Gravity is neglected,
Then PE=0
KE=0
Therefore E= U