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Chapter 15. Energy. Chapter 15.1 Energy and Its Forms. What is Energy? It is the ability to do work. It is transferred by a force moving an object through a distance. 2. What are the two general types of energy? Kinetic Energy Potential Energy. Chapter 15.1 Energy and Its forms.
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Chapter 15 Energy
Chapter 15.1Energy and Its Forms • What is Energy? It is the ability to do work. It is transferred by a force moving an object through a distance. 2. What are the two general types of energy? Kinetic Energy Potential Energy
Chapter 15.1Energy and Its forms A1. What is Kinetic Energy? The energy of motion Comes from the Greek word kinetos, “moving” A2. What does Kinetic energy depend upon? Mass and speed A3. What is the formula for Kinetic Energy? KE = ½ mv2
Chapter 15.1Energy and Its forms A4. Math Skills on Page 448 A 0.10-kilogram bird is flying at a constant speed of 8.0 m/s. What is the bird’s kinetic energy? List, show formula, sub, math, answer! Math Practice on page 448 • 140 joules • 440,000 joules • 27 m/s
Chapter 15.1Energy and Its forms B1 What is Potential Energy? It is energy that is stored as a result of position or shape. Potential Energy is converted into Kinetic Energy! B2 What are two forms of potential energy? Gravitational potential energy Elastic potential energy B3 What are some examples? Plucking a string and lifting a book
Chapter 15.1Energy and Its forms B4. What is gravitational potential energy? Potential energy that depends upon an object’s height Higher the height, greater the PE B5. What is elastic potential energy? Potential energy of an object that is stretched or compressed Greater the stretched or compressed, greater the PE
Chapter 15.1Energy and Its forms B6. What is the formula for gravitational potential energy? PE = m x g x h
Chapter 15.1Energy and Its forms Suppose the diver at the top of a 10.0 meter-high diving platform has a mass of 50.0 kilograms. What is her potential energy? A pear is 3.5 meters above the ground and has a mass of .14 kg. What is the pear’s potential energy?
Chapter 15.1Energy and Its forms C1. What are the final two forms of potential energy? Chemical Energy It is the energy stored in chemical bonds. When bonds are broken , the released energy can do work.
Chapter 15.1Energy and Its forms Nuclear Energy It is the energy stored in atomic nuclei It involves two forces, strong and weak.
Chapter 15.1Energy and Its forms What are the different forms of Kinetic energy? Light (EMR) Electricity Sound (Mechanical) Wind (Mechanical) Thermal (Heat)
Chapter 15.1Energy and Its forms Mechanical Energy The energy associated with the motion and position of everyday objects. Speeding trains, bouncing balls, wind, and sound Thermal Energy It is the energy needed to make the atoms move faster.
Chapter 15.1Energy and Its forms Electrical Energy It is the energy associated with electric charges. Batteries Lightning bolts Electromagnetic Energy It is a form of energy that travels through space in the form of waves Ultraviolet Roy G Biv
Chapter 15.2 EnergyConversion & conservation • What is energy conversion? Energy can be converted from one form to another. 2. What are the different conversions for lighting a match?
Chapter 15.1 EnergyConversion & Conservation 3. What is the law of conservation of energy? Energy cannot be created or destroyed. Energy can be converted from one form to another.
Chapter 15.2 EnergyConversion & Conservation 4. What is the most common energy conversion? The gravitational potential energy of an object is converted to the kinetic energy of motion as the object falls.
Chapter 15.2 EnergyConversion and Conservation 5. What is a pendulum? It consists of a weight swinging back and forth from a rope or string. Kinetic energy and potential energy undergo constant conversion as a pendulum swings.
Chapter 15.2 EnergyConversion & Conservation 6. How do we find the total amount of energy (Mechanical Energy)? ME = KE + PE ME = ½ mv2 + mgh
Chapter 15.2 EnergyConversion &Conservation 7. Math Skills on page 458 List, formula, sub, work, answer Add on question: How high is the rock? 8. Math Practice on Page 458
Chapter 15.2 EnergyConversion &Conservation 9. What is the relationship between Energy and Mass? Energy and mass are equivalent and can be converted into each other. 10. What is the formula for this relationship? E = mc2 Albert Einstein Special theory of relativity in 1905
Chapter 15.2 EnergyConversion & Conservation 11. How much energy does 1 gram of mass have when converted to energy? C = 3.0 x 108 m/s List, formula, sub, answer Answer = 9 x 1013 joules
Chapter 15.3 Energy Resources • What are the two types of energy resources? Nonrenewable and renewable 2. What are nonrenewable energy resources? They exist in limited quantities and, once used, cannot be replaced except over the course millions of years. Resources are oil, natural gas, coal, and uranium.
Chapter 15.3 Energy Resources 3. What are renewable energy resources? They are resources that can be replaced in a relatively short period of time. Resources are hydroelectric, solar, geothermal, wind, biomass, and possibly in the future, nuclear fusion
Chapter 15.3 Energy Resources Hydroelectric Energy energy obtained from flowing water. Solar Energy sunlight that is converted into usable energy. Geothermal Energy thermal energy beneath Earth’s surface. Biomass Energy the chemical energy stored in living things
Chapter 15.3 Energy Resources Hydrogen Fuel cell generates electricity by reacting hydrogen with oxygen. 4. What is energy conservation? Energy resources can be conserved by reducing energy needs and by increasing the efficiency of energy use.
