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Energy
What is energy?
What is energy? Energy is the capacity of anobject or body to transform an energy source into work.
The quantity of energy isthe equivalent of the quantity of work.
Units of energy • The international System (IS)
measures energy in joules (J) and kilojoules.
1000 J = 1 KJ
• Heat energy is often measured in units called calories (cal) and Kilocalories (kcal).
1 cal = 4,18 J
Different types of energies
Muscle energyYears ago, muscle energy was the main source of energy, but we have invented different mechanisms and machines that have improved our quality of life.
For example:★ Bicycles need our muscle energy when we move the
pedals.★ Kitchen appliances need electricity to work, as
televisions and computers.
Mechanical Energy
★Kinetic Energy
★Potential Energy
Electrical energy
Electromagnetic energy
Sound energy
Chemical energy
Nuclear energy
Thermal or calorific energy
POWER
t
W is work, measured in joules (J)
t is time, measured in seconds (s)
P= W
P is power, measured in watts (W)
The power of a machine is the quantity of work it can do per unit of time. Power is expressed in the formula:
Transformation of energy
It’s when we transform an initial form of energy into other forms of energy.
Examples: Chemical to electrical energy, luminous to electrical energy...
Energy sources
What is?
Energy sources are natural resources that provide different forms of energy. This energy is transformed for specific uses. They are classified into:
● renewable sources
● non-renewable sources
Renewable energy sources
Hydraulic energy
Solar energy:
➔Termal system:
➔Photovoltaic energy:
Wind energy
Marine energy
➔ Tidal energy:
➔ Wave energy:
➔ Ocean Thermal energy:
Geothermal energy
Biomass
Municipal solid waste
Nuclear energy
Coal
Petroleum
Natural gas
Non- Renewable energies and the environment
Green house effect
Acid Rain
Oil Spills
Nuclear Waste
Rising Water temperature
Atmospheric Pollution
THE ENDBy: Berta Parera, Marta Pera & Guisla Roig.
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