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Zorluk: OrtaModes of Heat Transfer (Conduction, Convection, and Radiation)

Match each vacuum flask component or surface feature on the left with its primary mechanism for controlling heat transfer on the right.

  • Silvered inner surfaces of the double wallsMinimizes heat loss by thermal radiation through reflection
  • Evacuated space (vacuum) between the wallsEliminates heat transfer by conduction and convection due to absence of a material medium
  • Cork stopper at the top openingPrevents heat loss primarily by convection of trapped air and conduction through bad conductors
  • Dull black exterior casingMaximizes the emission or absorption of thermal radiation

Cevap

Silvered inner surfaces match with radiation reflection; evacuated space matches with elimination of conduction and convection; cork stopper matches with prevention of convection and conduction at the opening; dull black casing matches with maximizing thermal radiation emission/absorption.
Each feature of the vacuum flask targets a specific heat transfer mode: silvering reflects infrared radiation; the vacuum eliminates particle-dependent transfer (conduction and convection); cork acts as an insulator preventing convection and conduction at the top; and black surfaces maximize thermal radiation emission/absorption.

Adım Adım Çözüm

1
Analyze the silvered inner walls of a vacuum flask
Silver surfaces are good reflectors of heat rays (infrared waves).
Radiant heat travels via electromagnetic waves and is reflected by shiny metallic coatings, minimizing radiation heat loss.
2
Analyze the vacuum space between the glass walls
Conduction and convection cannot occur across a vacuum.
Both conduction (particle vibration/electron flow) and convection (fluid movement) strictly require a physical medium.
3
Analyze the cork/plastic stopper
Cork prevents hot air circulation and thermal conduction across the opening.
Cork is a poor conductor of heat and stops evaporative/convective air currents from leaving the container.
4
Analyze the dull black exterior
Dull black surfaces are efficient radiation emitters/absorbers.
According to radiation principles, black matte surfaces radiate energy much faster than polished surfaces.

Anahtar Kavram

Modes of Heat Transfer and Practical Applications in Thermal Insulation
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Konular

Modes of Heat Transfer (Conduction, Convection, and Radiation)

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