Energy Continued Unit 5 – Lecture 2.
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Transcript of Energy Continued Unit 5 – Lecture 2.
![Page 1: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/1.jpg)
Unit 5 – Lecture 2
![Page 2: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/2.jpg)
Review: PE & KEPotential Energy – “stored” E Kinetic Energy – energy of motion /
“released” E
![Page 3: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/3.jpg)
Conservation of EnergyLaw of Conservation of Energy:
energy can neither becreated nor destroyed in normal reactions
energy can be changed in form from one to another
initial energy = final energyenergy in = energy outaka 1st law of thermodynamics
![Page 4: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/4.jpg)
Mechanical EnergyMechanical E – total amount of PE & KE in a
systemas PE decreases, KE increasesas PE increases, KE decreaseswhat kind of relationship is this…direct or
inverse?
![Page 5: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/5.jpg)
Mechanical EnergyEquation:MEinitial = MEfinal
(PE + KE)initial = (PE + KE)final (m g h + ½ m v2 )initial = (m g h + ½ m v2 )final
![Page 6: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/6.jpg)
![Page 7: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/7.jpg)
Mechanical EnergyME in a pendulum:
![Page 8: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/8.jpg)
PracticeAt which point…is GPE at a maximum?
why?is KE at a maximum?
why?
![Page 9: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/9.jpg)
Practice Which of these describes E? [any]Ability to do work Ability to cause changeAbility to increase energy Ability to decrease
work
Joules is NOT a unit for which of these?PE KEForce Work
![Page 10: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/10.jpg)
Forms of EnergyMechanical Energy
energy of an object due to its motion [kinetic E] or position [potential E]
![Page 11: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/11.jpg)
Forms of EnergyElectromagnetic E
waves of mostly invisible E
light energy often is converted into thermal E
can be converted into chemical E through photosynthesis
![Page 12: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/12.jpg)
![Page 13: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/13.jpg)
Forms of EnergyChemical E
stored and released in the bonds between atoms
food, batteries
![Page 14: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/14.jpg)
Forms of EnergyNuclear E
stored and released from the nucleus of an atom
![Page 15: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/15.jpg)
Forms of EnergyThermal E
heat in all its forms and flows
recall – exothermic & endothermic
transferred through conduction, convection, & radiation
![Page 16: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/16.jpg)
Forms of EnergyElectrical E
separation and movement of electrons[not really a form of E
on its own – it is a combination of forms of Mechanical and Electromagnetic E]
![Page 17: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/17.jpg)
PracticeWhen you are watching tv, what energy
conversions are taking place?Which energy transformation takes place
when a match is struck against the side of a matchbox and bursts into flames?
What causes you to hear something? What kind of energy is sound?
![Page 18: Energy Continued Unit 5 – Lecture 2.](https://reader035.fdocuments.net/reader035/viewer/2022062317/5a4d1b097f8b9ab059989b81/html5/thumbnails/18.jpg)