Physics T1 - Reducing unwanted energy transfers
- Created by: Claudiacumberpatch
- Created on: 11-03-20 19:12
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- Reducing unwanted energy transfers
- Lubrication reduces energy transferred by friction
- 1.)Whenever something moves at least 1 frictional force acting against it
- 2.) This transfers energy mechanically (work is done against friction) to thermal energy store of objects involved, which is dissipated by heating surroundings
- 3.) For objects touching lubricants used to reduce friction between objects' surfaces when they move, lubricants are liquids (like oil) so can flow easily between objects & coat them
- Insulation reduces rate energy transfer by heating
- 1.) When 1 side object heated particles in hotter part vibrate more & collide this transfers energy from their kinetic energy stores to other particles which vibrate faster
- 2.) Process called conduction transfers energy through the object
- 3.) All materials have thermal conductivity - how well a material transfers energy by conductivity (metals have high thermal conductivity, gases have low thermal conductivity
- 4.) In buildings the lower the thermal conductivity of its walls the slower the rate of energy transfer between them (meaning building will cool more slowly)
- 5.) Some houses have cavity walls, made up of inner & outer wall with air gap in middle, air gap reduces amount of energy transferred by conduction as air has very low thermal conductivity
- 6.) Thicker walls help too - thicker the wall slower the rate of energy transfer
- Lubrication reduces energy transferred by friction
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