1. ENERGY

2. Below are several statements. Decide which of them you agree with them or disagree with the statement. Write a sentence or two describing the reasoning behind your choice. AGREE DISAGREE Heat energy is the kinetic energy of the randomly moving particles in a substance. AGREEDISAGREE The tiny particles that make up all matter can be seen under a microscope. AGREEDISAGREE Energy can be transferred through solids because the particles are held together by flexible connections. AGREEDISAGREE

3. What do you think of when you hear the word ENERGY? Food Movement Doing things Working Sunlight

4. Where do they get the energy to go down the hill? Why is energy so important to us? Energy

5. EVERYDAY ENERGY? What types of energy do you encounter everyday? How does energy get from one place to another? It will either transform or transfer.

6. So what is ENERGY?!?! Energy is NOT matter and is actually very difficult to define... Textbooks define it as … “ The ability to do work ” We will define it by providing examples of energy and the effects it has on objects. There are many different types of energy…

7. Types of Energy We have already talked about many different types of energy. ALL energy can be classified as either Potential Energy or Kinetic Energy.

8. Gravitational POTENTIAL Energy (GP E ) Gravitational Potential Energy (GP E ) is the stored energy of an object resulting from the position of the object in a system. GP E relies on the height of the object in the system…the higher the object the more GP E it has. If you add GP E to K E you get Mechanical Energy (M E ). ME= GPE + KE

9. Kinetic Energy (KE) Kinetic Energy (KE) - the energy of motion. The energy associated with moving objects is called kinetic energy (KE), and is often referred to as the most fundamental form of energy. The size of the KE is determined by an object ’ s speed and its mass.

10. Review of Energy Forms

11. Kinetic Energy (KE) - the energy of motion. The energy associated with moving objects is called kinetic energy (KE), and is often referred to as the most fundamental form of energy. The size of the KE is determined by an object’s speed and its mass. A moving baseball has kinetic energy. If you have ever been hit by a pitched ball, you are aware of the energy a moving object can have. Gravitational Potential Energy (GPE) - the stored energy of position. This is energy that an object possesses due to its position. The size of the GPE is determined by the object’s mass and its height above the ground. A person climbing a ladder increases her height above the ground, she increases her GPE. Mechanical Energy

12. Heat Energy (HE) - the random kinetic energy of particles. Heat energy is the random, and very disorganized, kinetic energy of the particles in a substance. The thermal energy of an object consists of the total kinetic energy of all its atoms and molecules. It is a form of energy related to heat and temperature. Thermal energy can be created internally with chemical, nuclear and electrical reactions. It can also be created or increased from external effects, such as mechanical motion, radiation and thermal conduction.

13. Chemical Energy (CE) - The energy held in the covalent bonds between atoms in a molecule is called chemical energy. Every bond has a certain amount of energy. To break the bond requires energy, it is called endothermic. These broken bonds then join together to create new molecules, and in the process release heat, chemists call this exothermic. If the total heat given out is more than the heat taken in then the whole reaction is called exothermic, and the chemicals get hot.

14. Electromagnetic Energy –Electromagnetic energy is the energy that comes from electromagnetic radiation. This radiation is composed of waves, such as radio waves and visible light, that move at the speed of light in a way that is suggestive of both waves and particles. Electromagnetic radiation causes both electric and magnetic fields. Only a small part of the electromagnetic field is visible; this part of the electromagnetic spectrum is known as the visible spectrum.

15. Sound Energy-Sound energy is the energy produced by sound vibrations as they travel through a specific medium. Sound vibrations cause waves of pressure which lead to some level of compression and rarefaction in the mediums through which the sound waves travel. Sound energy is, therefore, a form of mechanical energy; it is not contained in small particles and it is not related to any chemical change, but is purely related to the pressure its vibrations cause. Sound energy is typically not used for electrical power or for other human energy needs because the amount of energy that can be gained from sound is quite small.

16. Elastic Potential Energy (EPE) - Elastic potential energy is the potential energy of an elastic object (for example a bow or a spring) that is deformed under tension or compression (often termed under the word stress by physicists). It happens as a result of a force that tries to restore the object to its original shape, which is most often the electromagnetic force between the atoms and molecules that make up the object. If the stretch is released, it is transformed into mechanical energy.

17. Salem Nuclear Power Plant Nuclear Power- Nuclear power plants split the nuclei of uranium atoms in a process called fission. The sun combines the nuclei of hydrogen atoms in a process called fusion. Scientists are working on creating fusion energy on earth, so that someday there might be fusion power plants.

18. Chemical Energy vs. Nuclear Energy Chemical Energy It is the energy that holds electrons together that move around the nucleus. Happens in the Electron Cloud The energy can be released when the bonds are broken. Small Amount of Energy released Examples Digestion, burning fossil fuels Nuclear Energy It is the energy stored in the nucleus of an atom. Happens in the Nucleus The energy can be released when the nuclei are combined or split apart. Large amount of Energy released Examples Sun,x-rays, Nuclear Power

19. What ’ s the Difference between energy transfer and energy transformation? Give an example of each. Energy transfer is when the same energy is transferred to another object. When you kick a soccer ball down the field with your moving leg! (transferring energy from your leg to the ball) Energy transformation is when one energy type changes into another type of energy. A rollercoaster that is stopped on top of the hill rolls down the track. (PE-KE)

20. Energy in Systems Energy can move from place to place or change from one type to another… Energy transformation – is changing from one type of energy into a different type of energy. Energy transfer - is how the same type of energy is passed from one object to another object.

21. Dropping Golf Balls... You will drop a golf ball and a fuzzy ball from four different heights (25cm, 50cm, 75 cm and 100cm) looking for evidence of energy by a change that is produced by each one.

22. Let ’ s Investigate At each lab station you will find a piece of paper with 7 Questions and a set of directions from A-D. (Do NOT write on these sheets.) You must do these in order… so if some Questions come first, answer the question BEFORE going on to the direction steps!!! Answer the questions on the dry erase board neatly. You may discuss the answers as a group, but do NOT copy answers from other groups…write your own!!!

23. Set up a Data Table 1.Make a data table 2.One column for the golf ball and one column for the fuzzy ball. 3.Use little ruler to measure the width of the crater in cm. 4.Then Use the ruler to smooth the sand. 5.Record your answers. 6.Clean up when you are finished! Answer post lab questions. Heights Golf Ball Fuzzy Ball Height (cm) Width of Crater (cm) 25 50 75 100

24. Investigation Results 1.) The golf ball does not have any K E since it is not moving. It does not have the ability to move on its own due to its position (sitting in the sand) so it does not have any GP E. If K E = 0J and GP E = 0J then M E is also 0J!!! 2.) The golf ball now has GP E b/c it is above the ground… it now has a height of 25cm!!! It does not have K E though since it is not moving.

25. Investigation Results 3.) The golf ball got its energy from the person who picked it up and moved it to a height!!! The person TRANSFERRED energy to the ball from themselves when they lifted it!!! This energy came from the person ’ s muscles. The muscles got their energy from the food you ate. Tracing this flow of energy is called an ENERGY CHAIN.

26. Investigation Results 4.) The ball dropped from the highest point = 100cm caused the biggest crater. 5.) The variable that changed here was the MASS of the ball. Everything else remained constant (stayed the same). The craters produced by the hollow ball w/ less mass were smaller. Mass affects GP E and K E !!!

27. Investigation Results 6.) Both of the balls hit the sand at the same speed!!! (In other words, they fall at the same time!!!)…Watch I ’ ll show you… The difference between the two balls is the amount of energy!!! The more massive ball possesses more energy!!!

28. Investigation Results 7.) The big point you should have concluded is that MASS affects both GP E and K E. You should have also concluded that the higher the release point, the faster the ball will be traveling when it hits the sand. Gravity speeds up ALL falling objects at the same rate (9.8 m/s 2 ). The greater the speed of the object when it hits the sand, the greater the K E.

29. LAW OF CONSERVATION of ENERGY

30. In the golf ball investigation, can we account for all the energy in the system? Basically, if we add up all the PE, KE and any friction, will it equal the total energy (TE) in the system? Yes, scientific evidence leads us to believe that ALL of the energy in any example can be accounted for! But it is not always easy in an open system.

31. LAW OF CONSERVATION of ENERGY Energy cannot be created or destroyed; it can only be transformed or transferred. Total Energy is all the energy in a system The TOTAL ENERGY (T E ) will always stays the same!!! T E = P E + K E + heat

32. LAW OF CONSERVATION of ENERGY The TOTAL ENERGY of a system can be measured by adding P E + K E + Heat. T E = K E + P E + heat Q: Where does the heat come from??? A: Friction!!! (Rub your hands together and see what happens!!!)

33. LAW OF CONSERVATION of ENERGY TE will equal the GPE at the highest point in a system! TE=GPE at the highest point 100 Joules of energy to start 100 Joules of energy at the end! Equal at the mid point! “ What you put in, is what you get out! ” (TE) NEVER CHANGES in a system! A B C

34. LAW OF CONSERVATION of ENERGY Let ’ s look at the pendulum swing. Will it continue to swing with same amount of energy over time? Why won ’ t the beginning energy ever equal the end energy??? Hint: Can heat be contained in an open system? NO… please remember that energy is not destroyed, but some of it can escape from the system to the surroundings in the form of heat from the rope.

35. LAW OF CONSERVATION of ENERGY This is why no system will ever be 100% efficient… Meaning the beginning energy will never equal the end energy… There is no such thing as a frictionless system!!!

36. 2. In an energy chain, only KE and GPE are to be included. AGREEDISAGREE As energy is transferred and transformed in a system, some of the energy is lost. AGREEDISAGREE Work is the same thing as energy. AGREEDISAGREE If something has a lot of energy, it also has a lot of power. AGREEDISAGREE

37. ENERGY CHAINS Since energy is transferred and transformed all the time, it is helpful to be able to track the “ flow ” of energy in systems. A map of what happens to energy, where it goes, and how it changes is called an Energy Chain. Energy chains can be created using words, pictures, arrows, or any combination of things that show the movement of energy in an example.

38. Energy Chains Can you think of how the energy flows through a car? What would you start with? What types of energy transformations are happening?

39. Energy Transfer and Transformation Chemical Electrical Thermal Mechanical Kinetic Energy Thermal Energy

41. Can you construct an Energy Chain for a person hitting a softball to the outfield?

42. Hitting a softball into the outfield 1.Chemical E to pick up bat from food. 2.Ball has PE in the air 3.Ball throw in air transform from PE to KE 4.Bat hits ball transfers KE to ball 5.Ball increases KE 6.Gravity pulls on ball 7.Air resistance slows ball down 8. Ball hits ground (Friction) 9. Balls KE is transferred to dirt as it flies up.

44. Constructing Energy Diagrams

45. Using Font Size Predict what this car is doing? Coming to a stop! The KE is deceasing over time as it is being transformed in heat and PE energy.

46. A car stopping as a standard Bar Graph KE HE

47. Using Circle Graphs Circle graphs can be used to illustrate energy flow. Each form is a represented by a portion of the circle. Multiple circle graphs can illustrate how the amount of energy in each form changes over time.

48. Circle Graph Examine what is happening in these circle graphs? What do you notice at interval 4?

49. ENERGY CHAINS Let ’ s look at some systems where energy transformation is taking place…(i.e. changing from one type of energy to another type of energy.) Ramps Cars Bungee jumper A Pendulum A Hydroelectric Power Plant

50. Energy Ramp Label sections A-E w/ the appropriate level of P E and K E (Assume NO friction) Use the following terms Maximum High Medium Low Minimum PE= Max KE=Min KE= Max KE= High KE= Low PE= High KE= Med PE= Min PE= Low PE= Med

51. PENDULUM E C BD A At which point is the KE greatest? What is the velocity at that point? Point C 5.6 m/s

52. Pendulum Energy Transformation Draw this pendulum diagram on white board A. PE=KE? Points 2 and 4 B. PE greatest? Points 1 and 5 C. KE greatest? Point 3 only D. KE lowest? 1 and 5 E. PE lowest? 3 only

53. 1. Statement: The farther above the ground an object, such as a book, is raised, the greater the object ’ s Gravitational Potential Energy (GPE). Circle the statement below which most closely matches your thinking and then explain your thinking. 1.Yes, everything has some potential energy. 2. Yes, but it only gets potential energy when it falls. 3. Yes, because gravity is stronger the higher you go up. 4. Yes, one thing that determines the GPE is the distance between the object and the ground. 5. No, there is no force or motion happening. 6. No, it is not in contact with anything which could give it energy.

54. POTENTIAL energy (P E ) Potential Energy (P E ) is the stored energy of an object resulting from the position of the object in a system. P E is measured by multiplying the mass of the object times the gravity and then times the height. P E = m x g x h remember…(gravity = 9.8m/s 2 ) Units are Joules!!! (J) 1 Joule= 1kg x m 2 /s 2

55. POTENTIAL energy (P E ) Examples of objects with high P E : A stretched rubber band Any hanging object Any compressed object (like a spring) Any object that is high up

56. PE Power Triangle Plug P E = m*g*h into a Power Triangle Write the equations when you solve for m and h.

57. DUFAS It ’ s how we will solve ALL problems!!!

58. DUFAS D is for DATA U is for UNITS F is for FORMULA A is for ARRANGE S is for SOLVE

59. How DUFAS works … All problems will be worth 5 points. You will get 1 point for every DUFAS step. So…correct answers are only worth 1 point!

60. D is for DATA : Step 1: Pull out all of the DATA for the problem and label the numbers.

61. D is for DATA : Example: A mountain biker rides down a 42m high mountain with 2500 J of GPE. What is the mass of the mountain biker? What ’ s the formula for GPE? GPE= mgh Here ’ s what we know… h = 42m GPE = 2500J Are we missing anything? Gravity 9.8 m/s2

62. U is for UNITS : Step 2: ALL numbers throughout the ENTIRE problem must have CORRECT UNITS!!! h = 42m GPE = 2500J gravity = m/s 2

63. F is for FORMULA : Step 3: You must write the equation for EVERY problem. GPE=mgh

64. A is for Arrange : Step 4: You must re-arrange the original FORMULA to solve for the data you are missing. Will the formula GPE=mgh work? NO

65. A is for Arrange : Example: A mountain biker rides down a 42m high mountain with 2500 J of GPE. What is the mass of the mountain biker? ARRANGE to solve for m!!! (USE the POWER TRIANGLE!!!)

66. POWER TRIANGLE If there is a fraction in the formula then the variable at the top of the fraction goes on top of the triangle. Solve for mass So for m= PE gh

67. S is for Solve : Step 5: Now you need to arrange the data to SOLVE the formula. Put a box around your answer. Take two places past the decimal and Do not round your answer. m = PE gh2500J (kg x m 2 /s 2 9.8m/s 2 x 42m = 5.83 kg

68. Practice 1.) What is the height of a 2 kg apple that has 400 J of energy? 2.) A 80 kg man is about to sky dive from 20,000 m in the air. What is his PE? 3.) A train with 456,000 J of PE, is about to go down a 400 m mountain, what is the train ’ s mass?