Work:
Work is
said to be done if we apply force on a body and the body
moves in the direction of force applied. The work can be
calculated by the product of the force and the distance
through which a body moves.
i.e. Work done = Force (F) X
distance (d)
The work done is expressed in joule. Which is defined as
the work done when a force of 1 newton is applied on a body
through a distance of 1 metre?
Power:
The rate
of doing work is known as power.
i.e. Power = Work done/Time
taken
The power is expressed in joule/sec. or watt (1 watt =
1
Newton metre/second)
The bigger unit of power such as Horse power and Kilowatt
are also used. Where 1 Horse power = 746 watts and 1
Kilowatt = 1000 watts.
Energy:
Capacity
to do work is called energy. It has the same unit as that of
work i.e. joule. It can also be expressed in calories.
1 Calorie
= 4.18 joules
The energy can be in transition or is stored in the system
boundaries.
Examples of energy stored in the system are
1.
Potential
energy
2.
Kinetic
energy
3.
Internal
energy
Potential
energy (PE):
The energy
of a body by virtue of its height is known as potential
energy.
PE = mgh
Where m is the mass of body, g is gravitational
acceleration and h is the height through which body is
lifted.
Kinetic
energy (KE):
The kinetic of a body by virtue of its velocity is known as
Kinetic energy.
KE = ½ mv^{2}
Where m is the mass of the body and v is the velocity with
which it is moving.
Internal
Energy:
The balance energy is known as the internal energy.
Heat and
work
are the forms of energy in transition.
