Energy. Part 1: What is Energy?

Transcription

1 Energy Part 1: What is Energy?

2 What Is Energy? Energy takes many different forms and has many different effects. But what is it, exactly? Energy is the ability to cause a change. It could be a change in Shape Direction Speed Composition

3 2 Categories of Energy There are 2 main categories of energy: Kinetic Energy The energy of motion Found in things that are moving Potential Energy Energy that is stored Stored by position, shape or chemistry

4 9 Types of Energy The 9 types of energy fit in these 2 categories: Kinetic Energy Mechanical Energy Sound Energy Electromagnetic Energy Heat Energy Electrical Energy Potential Energy Gravitational Energy Elastic Energy Chemical Energy Nuclear Energy

5 Forms of Energy Review - Game 1 What form(s) of energy is found in each object? Mechanical Energy Sound Energy Electromagnetic Energy Heat Energy Electrical Energy Gravitational Energy Elastic Energy Chemical Energy Nuclear Energy

6 What 1 form Forms of energy of does Energy each - need Game to make 2 it work? A ceiling fan? A solar calculator? A wind-up toy? A skydiver? A battery? Mechanical Energy Sound Energy Electromagnetic Energy Heat Energy Electrical Energy Gravitational Energy Elastic Energy Chemical Energy Nuclear Energy

7 What form(s) Forms of energy of Energy do these - appliances Game 3 produce?

8 Measuring Energy Energy can be measured. In metric nations, it is measured in Joules (J) 1 joule is the equal to the energy needed to lift one apple from the floor to the table top. One Joule (1 J)

9 Measuring Energy Energy can be measured. Non-metric nations measure it in calories (cal). 1 calorie is the amount of energy needed to raise the temperature of water by 1 o C. One calorie (1 cal)

10 Energy Transfers Energy can change forms. Energy changes form during an energy transfer. For example, take a match Chemical Potential E Heat Energy Electromagnetic Energy

11 Energy Transfers Energy can change forms. Energy changes form during an energy transfer. Another example Gravitational Energy Kinetic Energy

12 Changing Forms Energy can change forms, but it is never lost. The Law of Conservation of Energy summarizes this: Energy cannot be created or destroyed. It can only be changed from one form into another. Let s take a look at that match again

13 Changing Forms Energy can change forms, but it is never lost. Energy cannot be created or destroyed. It can only be changed from one form into another. Chemical Potential E e.g J e.g J Heat Energy Light Energy

14 Energy Transfers Energy transfers can be shown with diagrams. They are called Energy Transfer Diagrams (ETD). To create an ETD, follow these steps: List the STARTING energy on the LEFT. List the FINAL energies on the RIGHT. Link them using an ARROW.

15 Energy Transfers Energy transfers can be shown with diagrams. They are called Energy Transfer Diagrams (ETD). Electrical Energy Electromagnetic Energy Heat Energy List the FINAL energies on the RIGHT. Electrical Energy à E-Mag Energy + Heat Energy

16 Energy Transfers Another example: Heat Energy Chemical Energy Electromagnetic Energy Sound Energy Chemical E à Heat E + E-Mag E + Sound E

17 Any Questions?

18 Energy Part 2: Energy Resources

19 Fuels There are different types of fuels: Coal, oil and gas are known as Fossil Fuels. Fossil fuels are made from the decomposed remains of living things that died over 250 million years ago.

20 Fossil Fuels The 3 fossil fuels are formed in different ways: COAL comes from the remains of dead plants OIL comes from the remains of dead sea creatures GAS comes from the remains of dead sea creatures

21 Fossil Fuels Fossil fuels are extremely valuable: They are used as fuel in cars and homes. They can be used to produce electricity. They are used to produce useful products: Plastics Rubber Medicines Fabrics Detergents Cosmetics

22 Advantages Fossil fuels have many advantages: They are an efficient source of energy. They are convenient to transport and use They are converted into many materials.

23 Disadvantages Fossil fuels have disadvantages as well: They produce pollutants when burned. They will eventually run out. This is why fossil fuels are called non-renewable energy resources.

24 Producing Electricity All energy resources use a turbine and a generator to produce electricity. A turbine is a propeller-like device which is made to spin. The turbine spins magnets inside the generator, which makes electricity.

25 e.g. Coal Power Plant A The coal The turbine generator plant hot steam burns spins, spins is coal which then to to produces shot boil turns water the electricity. generator. turbine. into steam.

26 Producing Electricity All energy resources use a turbine and a generator to produce electricity. Energy resources differ only by the way they cause the turbine to spin.

27 Renewable Resources Renewable resources will not run out. Renewable resources are continually replaced by the processes of nature. They are considered clean energy sources because they don t produce pollutants.

28 Renewable Resources Solar Energy Solar panels gather light energy to heat water in pipes. The water turns to steam, which is used to spin a turbine and a generator.

29 Mojave 2 Solar Plant

30 Renewable Resources Wind Energy The force of the wind in windy areas drives the blades of a wind turbine, which spins a turbine and a generator

31 Offshore Wind Farm

32 Renewable Resources Hydroelectric Energy Water stored high above a dam flows is allowed to flow down huge pipes. The rushing water spins a turbine and a generator.

33 Three Gorges Dam

34 Turbine Three Gorges

35 Renewable Resources Wave Energy The repetitive up and down movement of waves can be used to spin a turbine and a generator placed vertically in the sea.

36 Conceptual Wave Plant

37 Renewable Resources Tidal Energy During daily tides, water moves back and forth. The energy of the flowing water is used to spin turbine and a generator.

38 Tidal Power Plant

39 Renewable Resources Geothermal Energy In some locations, rocks below the surface are hot. Water is pumped through the rocks and is heated into steam. The steam spins a turbine and a generator.

40 Iceland Blue Lagoon

41 Renewable Resources Biomass Energy Plants, wood and animal waste can be burned as a fuel to heat water into steam. The steam is used to spin a turbine and a generator.

42 Wood Biomass Plant

43 Renewable Resources Renewables have many advantages: They will not run out. They do not produce pollution.

44 Renewable Resources Renewables have their disadvantages as well: They are not as efficient as fossil fuels. They are expensive to develop and run. Some can be an eyesore to look at.

45 Any Questions?

46 Energy Part 3: Energy in Foods

47 Introduction Food contains stored energy. Food contains chemical potential energy found in the molecules that the food is made from. Our body takes these molecules in and burns them in a process called cellular respiration

48 Energy In Food The energy in foods is measured in calories. 1 calorie is the amount of heat energy needed to raise the temperature of water by 1 o C.

49 Energy In Food The energy in foods is measured in calories. 1 calorie is the amount of heat energy needed to raise the temperature of water by 1 o C. But, energy values on most food labels say Calories One Calorie represents 1 kilocalorie, or 1000 calories!

50 Energy In Food

51 Energy In Food The energy in foods is measured in calories. 1 calorie is the amount of heat energy needed to raise the temperature of water by 1 o C. But, the energy values on most food labels say Calories This really says 180 Kilocalories, or 180,000 calories.

52 The Big Three The energy in food comes from 3 major substances, called macromolecules: Fats Carbohydrates Proteins

53 Fats Fats include come in two forms: solid (fats) and liquid (oils) Fats are useful for long-term energy, cushioning & insulation Fat-rich foods include nuts, butter, oils, cheese and meats

54 Carbohydrates Carbohydrates come in 2 forms: sugars and starches Carbohydrates are the body s main energy source (50%) Carb-rich foods include bread, cereals, pasta, fruit & veggies

55 Proteins Proteins are the building blocks of our cells and tissues Proteins are made out of smaller bits called amino acids Fat-rich foods include milk, eggs, meat, fish and beans

56 Energy Values Each type of macromolecule contains a different amount of energy, per gram. Carbs Proteins Fats 4 cal / g 4 cal / g 9 cal / g

57 Any Questions?