1. FAREEDA BEEGUM.R.S
PHYSICAL SCIENCE

2.  ENERGY is defined as the capacity or ability of a body
to do work.
 ENERGY has only magnitude and no direction.
 Whenever work is done , energy is consumed.
 S.I unit of energy is joule {J}.

3.  The amount of energy possessed by a body is
equal to the amount of work it can do when energy
is released.
 The object which does the work ……loses energy.
 The object on which the work done….gains energy.

4. VARIOUS FORMS OF ENERGY
 Potential energy.
 Kinetic energy.
 Heat energy.
 Chemical energy.
 Electrical energy.
 Light energy

5. Mechanical
energy
Kinetic energy Potential energy

6. KINETIC ENERGY
 ENERGY possessed by a body due to its motion is
termed as Kinetic energy.
 Kinetic energy increases with speed.
 If “m” is the mass and “v” is the velocity of the
body,
K.E ½ mv2

7. POTENTIAL ENERGY
 The energy possessed by a body due to its
relative position or configaration.
 The potential energy of an object at a height
depends on the ground level or zero level you
choose.
 If “m” is mass and “h” is height and “g” is the
acceleration due to gravity, potential energy
associated is given by
P.E mgh.

8. TRANSFORMATION OF ENERGY
The change of one form of energy in to
another form is known as
transformation energy.
1. When a body released from a height its P.E
changes to K.E.
2. When a body is thrown upwards the K.E of the
body is gradually changes or transformed in to
P.E.

9. EXAMPLES OF TRANSFORMATION OF
ENERGY
 At hydroelectric power station ,
P.E K.E Electric energy.
Steam Engine ,
Heat energy K.E
Thermal power station ,
Chemical energy heat energy electric
energy.

10. LAW OF CONSERVATION OF ENERGY
Energy can neither be created nor
be destroyed .The total amount of energy in
the universe remains the same. It only get
transformed from one form to another.