Heat And Energy Flashcards
What can increased the rate of heat transfer?
A bigger surface area so more infrared waves can be emitted from the surface
What are vacuum flasks?
Double walled with vacuum between to stop conduction and convection
Walls are silvered to keep heat loss through radiation minimal
Plastic stopper filled with cork to reduce heat conduction
How do humans control heat transfer?
Hairs on skin stand up to limit amount of heat loss
Larger ears in hot climates to help control heat transfer
Energy efficiency in the home?
Loft insulation Hot water tank jacket Double glazing Drought proofing Wall insulation
What is the most effective improvement to homes?
Draught proofing and double glazing
What is cavity wall insulation?
Foam between gap in bricks reduces convection and radiation
What is loft insulation?
Fibreglass wool across floor and ceiling reduces heat loss through conduction and convection
What is drought proofing?
Foam and plastic around doors and windows to stop heat loss through convection
What does a higher u value show?
Heat transfers faster through materials
What is specific heat capacity?
The amount of energy needed to raise the temp
What is the formula for specific heat capacity
Mass x specific heat capacity x temp change = energy transferred
Energy can …
Be transferred, stored but never created or destroyed
