unit 4 lecture chapter 15. energy and work energy is the ability to do work energy is measured in...
TRANSCRIPT
![Page 1: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/1.jpg)
Unit 4 Lecture
Chapter 15
![Page 2: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/2.jpg)
Energy and Work
• Energy is the ability to do work• Energy is measured in Joules (J)• Two types:• 1. Kinetic- movement• 2. Potential- stored
![Page 3: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/3.jpg)
Kinetic Energy
• Energy in motion• Kinetic Energy = ½ x mass x velocity2
• KE = ½ mv2
• KE is in Joules• Mass is in kg• Velocity is in m/s
![Page 4: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/4.jpg)
Practice Problems
• What is the kinetic energy of a jogger with a mass of 65.0 kg traveling at a speed of 3m/s?
What is the kinetic energy of a 1 kg pie travelling at a speed of 4 m/s ?
![Page 5: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/5.jpg)
Potential Energy
• 3 types:• 1. Chemical- energy in bonds ex: food, atomic
bomb• 2. Elastic- energy in things that compress and
stretch ex: rubberbands and springs• 3. Gravitational- objects suspended above
Earth
![Page 6: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/6.jpg)
Gravitational Potential Energy
• GPE= mass x gravity x height• GPE= m x g x h• GPE in Joules• Mass in kg• Gravity on Earth is 9.8 m/s2
• Height in m
![Page 7: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/7.jpg)
Practice Problems
• Find the gravitational potential energy of a light that has a mass of 13.0 kg and is 4.8 m above the ground.
• A cart at the top of a 300 m hill has a mass of 40 kg. What is the cart’s gravitational potential energy?
![Page 8: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/8.jpg)
Forms of Energy
• 1. Mechanical- motion and position, PE + KE• 2. Thermal- particles, PE + KE• 3. Chemical- chemical bonds and compounds• 4. Electrical- electric charges• 5. Electromagnetic- the EM Spectrum
(radiation spectrum)• 6. Nuclear- atomic bonds, atomic decay
![Page 9: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/9.jpg)
Energy Conversions
• Mechanical Energy = PE + KE• (PE + KE)start = (PE + KE)end
• Meteor falling and impact: KELightHeat• Wind up toys: PEKE• Lightbulbs: Elec ELight and Heat• Food: Chem PEKE + Heat• Falling Objects: GPEKE
![Page 10: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/10.jpg)
Energy Conversions in a Pendelum
![Page 11: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/11.jpg)
Law of Conservation of Energy
• Law of Conservation of energy states:• Energy cannot be created or destroyed• Energy changes form
![Page 12: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/12.jpg)
Theory of Relativity
• Energy = mass x speed of light2
• E = m x c2
• Energy in Joules• Mass in kg• Speed of light= 3.0 x 108 m/s
![Page 13: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/13.jpg)
Nonrenewable Energy
• Nonrenewable energy is in limited quantities because it takes millions of years to produce
• Ex: fossil fuels (coal, oil, natural gas)• Ex: elements (Uranium, Plutonium)• People have the desire to become more
efficient in order to reduce our usage.• Ex: energy star appliances, CFL lightbulbs,
hybrid cars
![Page 14: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/14.jpg)
Renewable Energy
• Renewable energy can be replaced in a much shorter time than nonrenewable
• 4 types:• 1. hydro- energy from flowing water ex: falling
water turns turbines• 2. solar- sunlight heats plates where water
flows through, rising steam turns turbines
![Page 15: Unit 4 Lecture Chapter 15. Energy and Work Energy is the ability to do work Energy is measured in Joules (J) Two types: 1. Kinetic- movement 2. Potential-](https://reader036.vdocuments.mx/reader036/viewer/2022062304/56649f2a5503460f94c43fe3/html5/thumbnails/15.jpg)
• 3. Geothermal- water is pumped into heated underground spaces which creates steam, rising steam turns the turbines
• 4. Biomass- chemical potential energy is stored in plants, burned or converted into ethanol
• 5. Wind- turns large turbines