Energy Table of Contents What Is Energy Forms

Energy Table of Contents What Is Energy? Forms of Energy Transformations and Conservation Energy and Fossil Fuels

Energy Learning Objectives 1. Describe how energy relates to work and power. 2. Describe kinetic energy and potential energy for various real world examples.

Energy from Your Food (Calorimetry Lab) Goal- Determine the amount of energy contained in a piece of food (a marshmallow). Procedure: 1. Fill the soda can with 20 m. L of water. 2. Measure the initial temperature of the water & the initial mass of the marshmallow (place the pie plate, marshmallow, paper clip, and clay on the balance), then the Mr. Nye will light the marshmallow about 1 inch underneath the soda can (held in place by you using tongs). 3. After the marshmallow is JUST finished burning, measure the final temperature of the water. 4. Then measure the final mass of the marshmallow. Again, place the pie plate, marshmallow, paper clip, and clay on the balance to get the final mass of the marshmallow. 5. Determine the temperature change (final – initial) and the mass change (initial – final) [both should be positive]. 6. Data Analysis: Calculate the number of Calories per gram of marshmallow: 7. cal/g = (20 g Water x 1 cal/g*o. C x Temperature change)/Change in mass 9. 8. 1000 calories = 1 Food Calories per gram = (previous calculation)/1000 10. Theoretical Yield = 3. 21 Food Calories/g 11. *Theoretical yield taken from the nutrition label (100 Food Cal/30 g). *

Energy Calorimetry Lab Conclusions Answer in the complete sentences… 1. How did your actual yield compare to theoretical yield of 3. 21 Food Cal/gram? Cal/gram 2. What are some sources of error in this experiment that would cause the actual yield to be considerably less than theoretical yield? Hints: Does all of the heat from the burning marshmallow go directly into the water? If not, then where does most of it go? 3. Keeping in mind that the grill lighter just got the burning started, where did the energy originally come from? How does this experiment demonstrate the reason as to why we need to eat food?

Energy Learning Objectives 1. Describe how energy relates to work and power. 2. Describe kinetic energy and potential energy for various real world examples.

Energy Introduction to Kinetic & Potential Energy is stored energy. Examples: Examples (Chemical) energy stored in a battery or food, a stretched rubber band (Elastic), or a person or an object at a high height (Gravitational) Kinetic Energy is the energy of movement or motion. Examples: Examples Any object or person that is moving has a certain amount of kinetic energy, Particles that make up matter are constantly moving.

Energy Kinetic vs. Potential Energy Experiment Goal: Determine the variables that affect the KE and PE for the go-car as it goes down the ramp for 2 different masses. Hypothesis: Predict how velocity will affect KE and how the height above the ground will affect PE. Background: m = mass, v = velocity, g = acceleration due to gravity, h = height above the ground Kinetic Energy (KE) = Energy of motion = 1/2 mv 2 Gravitational Potential Energy (PE) = Stored energy = mgh

Energy Machine Setup Mass Velocity KE Mass m v 1/2 mv 2 m (kg) (m/s) (J) (kg) Gravity g (m/s/s) Height h (m) Top of Ramp & no weights 0. 25 0 0. 25 9. 8 0. 5 Top of Ramp & weights 0. 50 0 0. 50 9. 8 0. 5 Bottom of Ramp & no weights 0. 25 From your data 0. 25 9. 8 0 Bottom of Ramp & weights 0. 50 From your data 0. 50 9. 8 0 PE mgh (J)

Energy Conclusions (in complete sentences) 1. State the relationships between the following variables (use the equations for help too): a) Velocity and KE b) Height above the ground and Gravitational PE 2. Where on the ramp would the KE & PE be about equal? Explain your answer with evidence from the experiment. Hint- Where was there 0 KE but plenty of PE and 0 PE but plenty of KE? 3. So, was any energy lost (outside of friction and human error), or was the energy transformed from one form to another (such as KE to PE or PE to KE)? How was the energy transformed as the gocar went down the ramp?

Energy Learning Objective 1. Describe kinetic energy and potential energy for various real world examples.

Energy - What Is Energy? Kinetic Energy Kinetic energy increases as mass and velocity increases.

Energy - What Is Energy? Potential Energy Gravitational potential energy increases as weight and height increase.

Energy - Energy Transformations and Conservation Energy Transformations Most forms of energy can be transformed into other forms.

Energy - Energy Transformations and Conservation Transformations Between Potential and Kinetic Energy A pendulum continuously transforms energy from kinetic to potential energy and back.

Energy What’s the difference between kinetic and potential energy? A. Kinetic energy is stored energy while potential energy is the energy of motion. B. Kinetic energy deals with movement while potential energy is stored energy. C. They are the same type of energy (just different names). D. I don’t know because I am not living up to my fullest potential.

Energy Which of the following would have the most kinetic energy? A. B. C. D. A person standing still on the ground. A person standing on a cliff. A bowling ball rolling at 2 m/s. A ping pong ball bouncing at 2 m/s.

Energy What happens to a car’s kinetic energy as it decelerates to a stop at a red light? A. B. C. D. The KE remains the same. The KE increases. The KE decreases. The KE increases, then decreases.

Energy Where on the diagram below would the ball have the most kinetic energy? A. B. C. D. Point A Point B Point C None of the above A B C

Energy Which of the following describes what happens to a basketball’s potential and kinetic energy as it falls down through the basketball hoop to the ground? A. B. C. D. The KE decreases while the PE increases. The KE increases while the PE decreases. The KE and PE both increase together. The KE and PE both decrease together.

Energy In which scenario would the skier have the most potential energy? A. B. C. D. A small skier at the top of a mountain. A small skier at the bottom of a mountain. A large skier at the top of a mountain. A large skier at the bottom of a mountain

Energy Which of the following best explains what happens to potential energy and kinetic energy as a skier goes down a mountain? A. Kinetic energy is transformed into potential energy as the skier goes down the mountain. B. Potential energy is transformed into kinetic energy as the skier goes down the mountain. C. Potential energy and kinetic energy both increase as the skier goes down the mountain. D. Kinetic and potential energy remain the same.

Energy Practice Test Answers 1 - The person who passed you is your reference point, so you’ll feel like you’re going slower. 2 - velocity (speed and direction) 3 - Walking then jogging & sled riding down a hill 4 - Motion 5 - Air resistance slows objects down in free fall. 6 - Friction 7 - Gravity causes objects to accelerate at 9. 8 m/s/s towards the Earth. 8 - House: greatest mass 9 - Moving a golf ball at 2 m/s/s

Energy 10 - Car at 20 mph Practice Test Answers 11 - lowering the applied force 12 - Greater than 1 13 - Wedge 14 - lower than the output force or load weight 15 - The smaller applied force is over a larger distance than the larger output force (which is over a shorter distance) 16 - Scissors, bike, car, human body, etc. 17 - Slow the object down and/or lower its mass 18 - Potential energy increases as kinetic decreases (as the snowball goes up higher); then the Potential energy decreases as kinetic energy increases (as the snowball goes down and increases in speed).

Energy Practice Test Answers 19 - Increase the distance (spread the objects farther apart) or lower the mass. 20 - Straight slanted line going up and to the right or down and to the right. 21 - Straight horizontal line going across 22 - Find the slope (rise/run = change in distance/change in time) 23 - Straight horizontal line; slanted line going down and to the right. 24 - 1 st and 2 nd class levers lower the applied force; 1 st class changes the direction of the force too. 25 - scissors, pliers, see-saw, crowbar 26 - Wheelbarrow, bottle opener, door

Energy Practice Test Answers 27 - The applied force should be pointing up the ramp. 28 - increase (M. A. = output force/input force) 29 - Moving fast and trying to stop but end up still moving forward; trying to move a heavy object from rest and it doesn’t move easily. 30 - Rocket taking off- Fuel burns (downward force) which causes the opposite reaction of the rocket moving upward; punching a wall- hit a wall and the wall pushes back (possibly causing injury)

Energy - What Is Energy? Using Prior Knowledge Before you read, look at the section headings and visuals to see what this section is about. Then write what you know about energy in a graphic organizer like the one below. As you read, write what you learn. 1. 2. What You Know The joule is the unit of work. Energy has different forms. What You Learned Power is the rate at which energy is transferred. The two basic kinds of energy are potential energy and kinetic energy.

Energy - What Is Energy? Links on Energy Click the Sci. Links button for links on energy.

Energy End of Section: What Is Energy?

Energy - Forms of Energy Calculating Mechanical Energy The kinetic energy of a 500 -N diver during a dive from a 10 -m platform was measured. These data are shown in the graph.

Energy - Forms of Energy Calculating Mechanical Energy Reading Graphs: According to the graph, how much kinetic energy does the diver have at 8 m? About 1000 J

Energy - Forms of Energy Calculating Mechanical Energy Calculating: Using the graph, find the kinetic energy of the diver at 6 m. Then calculate the diver’s potential energy at that point. Kinetic energy = about 2000 J; potential energy = about 3000 J

Energy - Forms of Energy Calculating Mechanical Energy Inferring: The mechanical energy of the diver is the same at every height. What is the mechanical energy of the diver? About 5000 J

Energy - Forms of Energy Building Vocabulary After you read the section, reread the paragraphs that contain definitions of Key Terms. Use the information you have learned to write a definition of each Key Term in your own words. Key Terms: Examples: mechanical nuclear energy A type The form of potential of energy associated calledwith nuclear the position energyand is motion in stored ofthe an nucleus object is of called an atom. mechanical energy. electromagnetic thermal energy The sunlight that you eachenergy day is of a form of total potential andsee kinetic the particles in electromagnetic an object is calledenergy. thermal energy. electrical energy The energy of electric charges is electrical energy. chemical energy Chemical energy is potential energy stored in the chemical bonds that hold chemical compounds together.

Energy - Forms of Energy Links on Forms of Energy Click the Sci. Links button for links on forms of energy.

Energy End of Section: Forms of Energy

Energy - Energy Transformations and Conservation Energy Transformations Most forms of energy can be transformed into other forms.

Energy - Energy Transformations and Conservation Transformations Between Potential and Kinetic Energy A pendulum continuously transforms energy from kinetic to potential energy and back.

Energy Physics-Related Jobs Job Title Description Salary Architect Design buildings and other structures Average $104, 000 Nuclear Physicist Work with nuclear reactors to provide clean energy $112, 000 -143, 000 Forensic Scientist CSI lab work (such as shot tracking) $49, 000 -62, 000 Radiation Technician Produce medical scans (such as XRays, CT scans, MRI’s, & sonograms) Average $58, 000 Research & Development Studies to help the world through Military Design (Weapons, Armor, Aircraft), Geophysics (Gas Drilling), Optical physics, Space physics, etc. $62, 000 -110, 000 (but can vary)

Energy Introduction to Chemistry Hindenburg. Hydrogen Gas Explosion Safety Protocol: 1. Do NOT touch anything on the back table until instructed to do so. 2. Follow Lab Directions (if you are unsure, then ask). 3. Notify teacher of spills, broken or breaking glassware, and any other problems.

Energy - Energy Transformations and Conservation Energy Transformations Activity Click the Active Art button to open a browser window and access Active Art about energy transformations.

Energy - Energy Transformations and Conservation Asking Questions Before you read, preview the red headings. In a graphic organizer like the one below, ask a question for each heading. As you read, write answers to your questions. Question What is an energy transformation? Answer An energy transformation is a change from one form of energy to another. What are some examples of transformations between potential and kinetic energy? Juggling and pendulums show transformations between potential and kinetic energy. What is conservation of energy? The law of conservation of energy states that energy cannot be created or destroyed.

Energy End of Section: Energy Transformations and Conservation

Energy - Energy and Fossil Fuels Use of Fossil Fuels Fossil fuels can be burned to release the chemical energy stored millions of years ago.

Energy - Energy and Fossil Fuels Previewing Visuals When you preview, you look ahead at the material to be read. Preview Figure 18. Then write two questions that you have about the diagram in a graphic organizer like the one below. As you read, answer your questions. Using Fossil Fuel Energy Q. What energy transformation occurs in the sun? A. Nuclear energy to thermal energy and electromagnetic energy Q. What energy transformation takes place when coal is burned? A. Chemical energy to thermal energy

Energy - Energy and Fossil Fuels Links on Energy Transformations Click the Sci. Links button for links on energy transformations.

Energy - Energy and Fossil Fuels Use of Fossil Fuels Click the Video button to watch a movie about the use of fossil fuels.

Energy End of Section: Energy and Fossil Fuels

Energy Graphic Organizer Energy exists as Potential energy Kinetic energy measured in is the ability to do Joules Work can be Elastic Gravitational which at a given rate is Power

Energy End of Section: Graphic Organizer