Transcript energy - bYTEBoss

ENERGY
Energy
the
ability to do work.
EFW
Work= Force x Distance
(W=F x D)
•
•
Work is done- same direction of F & D
ex: throwing a ball, pushing/pulling a chair
No work is done- different direction of F & D
and if no displacement/distance
ex: pushing a tree
*Unit of measurement--- J Joules (N x m)
KINDS OF ENERGY:
Kinetic Energy (KE)
-is energy in motion
-E of moving object)
ex: flowing water, flying bat
Potential Energy (PE)
-is energy at rest (due to its
position)
-stored energy
-E of stationary/not moving objects
ex: water in a glass, chicken adobo
Forms
of Energy:
1. Chemical Energy (CE)
2. Mechanical Energy (ME)
3. Electrical Energy (EE)
4. Sound Energy (SE)
5. Heat Energy (HE)
6. Radiant Energy (RE)
a. Solar E (UV Rays/Sunlight)
b. Light E (visible light)
c. Infrared Rays
d. X-rays
e. Radiation
7. Nuclear Energy (NE)
Law
of Conservation of Energy
“Energy is neither created nor
destroyed, it is only changed
from one form to another.”
 Energy Transformation
 Sun – main source of energy
Ex: washing machine ( EE to ME)
barking dog (CE to SE)
Television (EE to LE,HE,SE)
flash light (CE to LE,HE)
Sources
of Energy:
1. Renewable (unlimited)
- sources that can be replaced
within a short time after we use
them
a. Solar (sun)
b. Water
c. Tide (waves)
d. Geothermal Energy
(steam/vapor)
e. Wind
2. Non-renewable (limited)
-- sources that we are using faster
than they can replaced
a. fossil fuels (remains of plants
and animals)
- petroleum products –diesel,
gasoline, kerosene, LPG,
paraffin, grease
- coal
- natural gas (methane)
b. biofuel/biomass –from living things
- trees, sugarcane(alcogas),bacteria
Methods
 Heat
of Heat Transfer
energy or thermal energy is the energy
present due to the motion of its molecules.
 Heat always transfers, travels, or flows
from a high temperature to a low
temperature(hot to cold).
1. Conduction – is the transfer of heat
between substances that are in direct
contact with each other.
o The better the conductor, the more rapidly
heat will transfer.
o Metals are good conductors of heat.
o Solids (fastest) Liquid (faster) Gas (fast)
2.Convection – is the up and down
movement of gases and liquids caused by
heat transfer. (sinking of dense ,cold
gas/liquid and rising of less dense, hot
gas/liquid).
3.Radiation – is a method of heat transfer
in which energy is transmitted by waves
through space. (no direct contact)
o When the radiant energy strikes a body
where it is absorbed, the body becomes hot.
 The three methods of heat transfer can be
observed when boiling water in a beaker.
Heat
allows us to do work (cook
food, etc.); causes phase
change; causes expansion and
contraction; and causes
chemical change
(combustion/burning).