Flashcards
specific heat capacity & insulating buildings
Cards in this deck (11)
- 1What is specific heat capacity?the amount of energy needed to change the temperature of 1kg by 1C
- 2What is the equation for finding the energy transferred with the specific heat capacity?energy = mass x specific heat capacity x temperature change
- 3the _____ the mass of an object, the more slowly its ______ increases when it is heatedthe GREATER the mass of an object, the more slowly its TEMPERATURE increases when it is heated
- 4What does the temperature rise depend on, when a substance is heated?• the amount of energy supplied
• the mass of the substance
• what the substance is - 5Calculate the energy needed to increase the temp: • of 2kg of water • from 20C to 100C • the SHC of water is 4200 J/kg Cenergy = mass x temp x shc
= 2 x (100-20) x 4200
= 160 x 4200
E = 672000 J or 672 kJ - 6How are homes heated?electric or gas heaters and gas or oil central heating or solid-fuel stoves are used to heat homes
- 7Give examples of ways you can reduce the rate of energy transfer in your home.• loft insulation
• cavity wall insulation
• double glazed windows
• aluminium foil behind radiators
• external walls with thicker bricks and lower thermal conductivity - 8What is loft insulation?• ie. fibreglass- a good insulator
• reduces the rate of energy transfer through the roof
• air between the fibres helps reduce the rate of energy transfer
• the greater the number of layers of insulation, the thicker the insulation - 9What is cavity wall insulation?• reduces the rate of energy transfer through the outer walls of the house
• the insulation material used to fill the cavity between two brick layers
• traps air in small pockets
• reducing the rate of energy transfer by conduction - 10How does aluminium foil between a radiator and the wall reduce the rate of energy transfer?it reflects radiation away from the wall
- 11How do double glazed windows reduce the rate of energy transfer?• they are two glass panes with air between them
• the thicker the glass and lower its thermal conductivity, the slower the rate of energy transfer
• dry air is a good insulator
Information
- Description
- • 2.4: specific heat capacity • 2.5: heating and insulating buildings
- Created by
- Farha Idrees
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