unit 6 - energy

Energy

5th Grade

2015/2016

UNIT 6

WHAT IS ENERGY?

FORMS OF ENERGY -Thermal energy -Light energy -Electrical energy -Kinetic energy -Quemical energy -Nuclear energy -Mechanical energy -Sound energy

CHARACTERISTICS OF ENERGY

PART 1

ENERGY

https://www.youtube.com/watch?v=wyVF6R9e6xE

https://www.youtube.com/watch?v=NKJifzlOSoQ

https://www.youtube.com/watch?v=wyVF6R9e6xE

https://www.youtube.com/watch?v=NKJifzlOSoQ

ENERGY

-Plants use energy from the Sun to grow and make food. -Humans use energy from food to study, play basketball…

-Cars use energy from petrol to move.

What is energy? Energy is the ability to do work

ENERGY SOURCES

Energy comes from resources known as energy sources

The main energy source on Earth is……

Other energy sources are…..

ENERGY SOURCES

Energy comes from resources known as energy sources

The Sun is the main energy source on Earth. It gives us light and heat.

Other energy sources are: coal, oil, natural gas, uranium, water and wind.

FORMS OF ENERGY

Energy has different forms.

FORMS OF ENERGY

THERMAL ENERGY

Thermal energy is energy in the form of heat.

The thermal energy of an object depends on how fast its atoms and molecules are moving.

-If the atoms and molecules are moving very fast, the object will have a lot of thermal energy. Consequently, the temperature will be high.

-If the atoms and molecules are moving slowly, the object will have little thermal energy. Consequently, the temperature will be low.

THERMAL ENERGY

QUESTION 1 We’ve got a glass of water at 40°C and another glass of water at 20°C. Which glass has more thermal energy? Why?

QUESTION 2 Imagine we add ice to a glass of water, what do you think is going to happen with the thermal energy?

QUESTION 3 We put a metal saucepan of water on a hot stove. What is going to happen?

THERMAL ENERGY

QUESTION 1. We’ve got a glass of water at 40°C and another glass of water at 20°C. Which glass has more thermal energy? Why? The glass at 40°C because temperature is higher and molecules are moving faster.

QUESTION 2. Imagine we add ice to a glass of water, what do you think is going to happen with the thermal energy? We’ve got two objects with different temperature coming into contact. Thermal energy will be transferred from the glass of water to the ice, until they both are the same temperature. That is to say, the glass of water will emit heat and the ice cube will absorb heat. Consequently, the temperature of the water will fall and the temperature of the ice will rise.

QUESTION 3. We put a metal saucepan of water on a hot stove. What is going to happen?

We’ve got two objects with different ________________ coming into contact. Thermal energy will be transferred from the ____________ to the _____________, until they both are the same ___________________. That is to say, the stove will ___________heat and the water will ___________ heat. Consequently, the temperature of the water will ___________

THERMAL ENERGY

THERMAL ENERGY

QUESTION 4. What do these pictures show?

THERMAL ENERGY

QUESTION 4. What do these pictures show? They are expansion joints. In summer, roads get hot and they expand. Expansion joints allow When an object gets hot, it usually gets bigger. When an object gets cold, it usually gets smaller.

LIGHT ENERGY

Light energy is energy in the form of light.

Light energy is always moving, so we can’t store it.

Light travels in straight lines from its source.

Light travels at a speed of about 300.000 km/s.

LIGHT ENERGY

QUESTION 1 Can we see light?

QUESTION 2 Can you imagine a world without light?

LIGHT ENERGY

QUESTION 1. Can we see light? Light energy is the only form of energy we can see directly.

QUESTION 2. Can you imagine a world without light? Thanks to light we can see objects and distinguish their shape, size and colour. Also, plants need light to grow.

LIGHT ENERGY

QUESTION 3. Where does light come from?

LIGHT ENERGY

QUESTION 3. Where does light come from? Light sources emit light. They can be:

-Natural: the Sun, fireflies, jellyfish, fire

-Artificial: light bulb, fluorescent tube, matches, candles

LIGHT ENERGY

QUESTION 4. Can light pass through objects?

QUESTION 4. Can light pass through objects? Light can pass through some materials.

Transparent materials allow light to pass through them and objects can be seen clearly through them. For example: air, water, clear glass. Translucent materials allow some light to pass through them. Objects cannot be seen clearly through them. For example: sunglasses, curtains, stained glass windows. Opaque materials do not let any light pass through them. For example: wood, stone, cement and metals.

LIGHT ENERGY

ELECTRICAL ENERGY

It is energy in the form of electricity.

Electricity travels to homes and factories through metal cables. For example: -We use electricity in machines like computers and microwaves.

- A lamp plugged into a wall outlet takes the electrical energy and transforms it into light energy.

KINETIC ENERGY

Kinetic energy is found in moving objects.

If an object is moving, it has kinetic energy. All moving things have kinetic energy. For example: -A planet - A car - An ant - An atom

http://www.eschooltoday.com/energy/kinds-of-energy/what-is-kinetic-energy.html






















CHEMICAL ENERGY

Chemical energy is stored in some substances. It is released in a chemical reaction.

For example: - Chemical energy is stored in food and it is released during digestion.

-Chemical energy is stored in coal and it is released when we burn coal.

http://www.eschooltoday.com/energy/kinds-of-energy/what-is-chemical-energy.html




















NUCLEAR ENERGY

Nuclear energy is stored in the nucleus of an atom.

Scientists release nuclear energy in: - Nuclear fusion: atoms are combined together to form a

larger atom. - Nuclear fission: atoms are broken down to form smaller

atoms.

Uranium is a radioactive material used in nuclear power plants. http://www.eia.gov/kids/energy.cfm?page=nuclear_home-basics http://www.kids.esdb.bg/uranium.html

In nuclear plants, nuclear energy is transformed into electrical energy.

http://www.eia.gov/kids/energy.cfm?page=nuclear_home-basics











http://www.kids.esdb.bg/uranium.html











NUCLEAR ENERGY

Extracted from: http://tiki.oneworld.org/energy/energy7.html

SOUND ENERGY

Sound is the movement of energy through substances in waves.

http://www.eschooltoday.com/energy/kinds-of-energy/what-is-sound-energy.html





















Energy can be transformed into another form of energy.

Energy can’t be created and can’t be destroyed.

What happens when you talk on the phone?




When you talk on the phone, your voice is transformed into electrical energy, which passes over wires. The phone, on the other end, transforms the electrical energy into sound energy through the speaker.




How does a television work?




A television transforms electrical energy into light and sound energy

NON-RENEWABLE ENERGY SOURCES

- Oil - Coal - Natural gas - Uranium

RENEWABLE ENERGY SOURCES

- The Sun - Wind - Water

PART 2

NON-RENEWABLE ENERGY SOURCES

Non-renewable energy sources are found on Earth in limited amounts. It means that they run out as we consume them. For example: oil, coal, natural gas, uranium.

http://www.eschooltoday.com/energy/non-renewable-energy/what-is-non-renewable-energy.html














NON-RENEWABLE ENERGY SOURCES I

Oil is usually found underground. It is mainly used: - to produce fuels like petrol, diesel and fuel oil. - in chemical plants called refineries.

- to make plastics

Coal is extracted from surface mines. It is mainly used: - to produce electrical energy in power plants. - to make iron.

NON-RENEWABLE ENERGY SOURCES I

Natural gas is a mixture of gases (such as methane, propane, butane…)

It is used: -as fuel to produce electrical energy in power plants -for cooking -for heating.

Uranium is a white metal found in the Earth’s crust. It is very toxic. It is used in nuclear power plants to generate electrical energy. Energy from unarium is called nuclear energy.

RENEWABLE ENERGY SOURCES

Renewable energy sources are practically infinite. They never run out. For example: the Sun, wind and water.

http://www.eschooltoday.com/energy/renewable-energy/what-is-renewable-energy.html










RENEWABLE ENERGY SOURCES: THE SUN

Solar energy comes from the Sun. It provides us with:

-Light energy, which helps solar panels produce electrical energy. -Thermal energy, which solar panels use to heat water

Is solar energy always available??

RENEWABLE ENERGY SOURCES: THE WIND

Moving air produces wind energy. The moving air has huge amounts of kinetic energy. This kinetic energy can be transferred into electrical energy using wind turbines. The wind turns the blades of the wind turbines. The blades are connected to a generator. The generator makes electricity.

RENEWABLE ENERGY SOURCES: WATER

Hydraulic energy is the energy contained in water stored in reservoirs. Moving water has kinetic energy. This kinetic energy can be transformed into electrical energy in hydroelectric power plants. The water is stored in dams. Then, the water is released. The water moves a series of blades in a generator. This movement produces electrical energy. http://www.eschooltoday.com/energy/renewable-energy/hydro-energy.html

http://www.eschooltoday.com/energy/renewable-energy/hydro-energy.html













RISKS OF USING ENERGY

- Acid rain - Radioactivity - Resource depletion

PART 3

ACID RAIN (see pages 82 and 83 of the textbook)

ACID RAIN. Toxic gases are produced when fossil fuels, such as coal or oil, are burned. http://www.clean-air-kids.org.uk/acidrain.html

These gases combine with water vapour in the air and produce acid rain.

http://www.clean-air-kids.org.uk/acidrain.html




















- It takes away important minerals frohe leaves and the soil, which means that plants can’t grow properly, they become very ill and they can even die.

-Fish and plants living in lakes can die as well.

-Water we drink from taps can be polluted by acid rain, which can damage our brain.

-Air we breathe can be polluted, which can cause breathing problems and even cancer.

-Acid rain can also damage some materials used in buildings.

-It takes away important minerals from the leaves and the soil, which means that plants can’t grow properly, they become very ill and they can even die.

-Water we drink from taps can be polluted by acid rain, which can damage our brain.

-Acid rain can also damage some materials used in buildings.

ACID RAIN CAN BE VERY HARMFUL TO THE ENVIRONMENT

ACID RAIN (see pages 82 and 83 of the textbook)

RADIOACTIVITY Nuclear plants generate radioactive waste. Read the speech bubble and answer:

Do you think radiation is good for living things?


RADIOACTIVITY (see pages 82 and 83 of the textbook)
















RADIOACTIVITY (see pages 82 and 83 of the textbook)

RADIOACTIVITY. Nuclear plants generate radioactive waste. Do you think radiation is good for living things? Not at all. Radiation is harmful to all living things. It can cause diseases, such as cancer. http://tiki.oneworld.org/energy/energy7.html

http://tiki.oneworld.org/energy/energy7.html










RESOURCE DEPLETION (see pages 82 and 83 of the textbook)

RESOURCE DEPLETION It refers to the consumption of a resource faster than it can be replenished.

unit 6 - energy

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