Work is done when a force causes an object to undergo displacement. Work is calculated as the product of the force (F) and displacement (s) in the direction of the force (W=Fs). Energy is the ability to do work and exists in various forms including mechanical, heat, electrical, sound, light, and chemical. Mechanical energy exists in two forms: kinetic energy, which is the energy of motion calculated as one-half the mass (m) times the velocity (v) squared (K=1/2mv^2); and potential energy, which is the energy due to an object's position or strain and is calculated as the product of mass (m), gravitational acceleration (g), and height (

1. WORK
ENERGY AND
POWER
ARSHA RAMESH
ROLL NO.31
REG.NO.DD16EDPS01
PHYSICAL SCIENCE
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Presented by,

2. Objects undergo displacement
only when force is applied on
them
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4. WORK
Work is said to be done only when
a body undergoes displacement
under the action of a force
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5. If a force of F newton is applied
continuously on a body undergoes a
displacement of s metre in the
direction of the force, then the work
done by the force is …
W = Fs
Unit of work is joule
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8. ENERGY
Energy is the capacity to do work 8

9. VARIOUS FORMS OF ENERGY
Mechanical energy
Heat energy
Electrical energy
Sound energy
Light energy
Gravitational energy
Chemical energy etc…
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10. MECHANICAL ENERGY
There are two types of energy
1.KINETIC ENERGY
2.POTENTIAL ENERGY
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11. KINETIC ENERGY
The energy possessed by a body by
virtue of its motion is the kinetic
energy
When a body moves with a velocity
v its kinetic energy is
K = ½ mv2
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12. POTENTIAL ENERGY
The energy possessed by a body
due to its position or strain is
the potential energy.
Potential energy,
U = mgh
m → mass of object
g →acceleration due to gravity
h → height
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13. EXAMPLES…
POTENTIAL ENERGY
 Water in dam
 Elongated rubber
band
 Stretched bow
 Water in a tank etc.
KINETIC ENERGY
 Running train
 Mango falling from
tree
 Flowing river
 Flying bird etc.
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14. LAW OF CONSERVATION OF ENERGY
Energy can neither be created
nor destroyed. One form of
energy can only be converted to
another form.
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16. POWER
Work done per unit time is power.
Power = work/ time
Unit of power is watt.
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