Heat transfers in a thermos flask

A vacuum flask is designed to reduce the rate of heat transfer. What method of heat transfer are reduced by the silvered surfaces?

• Conduction

• Convection

• Radiation

Which surfaces are the best absorbers and emitters of radiation?

• Light and shiny

• Light and dull

• Dark and shiny

• Dark and dull

Tags

NGSS.HS-PS4-5

Which surfaces are the poorest absorbers and emitters of radiation?

• Light and shiny

• Light and dull

• Dark and shiny

• Dark and dull

Tags

NGSS.HS-PS4-3

A vacuum flask is designed to reduce the rate of heat transfer. What methods of heat transfer are reduced by the plastic cap?

• Convection and radiation

• Conduction and convection

• Conduction and radiation

Tags

NGSS.HS-PS3-4

What material is the best conductor of heat?

• Plastic

• Paper

• Metal

• Glass

Tags

NGSS.MS-PS3-3

Inside the thermos flask is a silver bottle. What heat transfer will the silver bottle reduce?

• Conduction

• Convection

• Radiation

Why does a vacuum reduce heat transfer by convection and conduction?

• Because the vacuum sucks the heat away

• Because the vacuum doesn't contain particles

• Because the vacuum stops all transfers of heat

Tags

NGSS.HS-PS3-4

The diagram shows a gas flame patio heater. Why is the top surface of the reflecting hood a light, shiny surface rather than a dark, matt surface?

• Because light shiny surfaces are poor emitters of radiation

• Because customers prefer light shiny surfaces to dull black surfaces

• Because dull, matt surfaces are poor emitters of radiation

Tags

NGSS.HS-PS3-4

The plastic cap or stopper is often made of plastic. How does this reduce heat transfer

• It is a good insulator so reduces conduction

• It is a good conduction so reduces convection

• It is shiny so reduces radiation

Tags

NGSS.HS-PS3-4

Glass and plastic are both good thermal insulators. What could a disadvantage of using glass be?

• Glass is transparent so you'd be able to see the liquid inside

• The glass is brittle and can break if dropped

• Glass would melt if hot water is added