Created by Farha Idrees
almost 6 years ago
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Question | Answer |
What is specific heat capacity? | the amount of energy needed to change the temperature of 1kg by 1C |
What is the equation for finding the energy transferred with the specific heat capacity? | energy = mass x specific heat capacity x temperature change |
the _____ the mass of an object, the more slowly its ______ increases when it is heated | the GREATER the mass of an object, the more slowly its TEMPERATURE increases when it is heated |
What 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 |
Calculate the energy needed to increase the temp: • of 2kg of water • from 20C to 100C • the SHC of water is 4200 J/kg C | energy = mass x temp x shc = 2 x (100-20) x 4200 = 160 x 4200 E = 672000 J or 672 kJ |
How are homes heated? | electric or gas heaters and gas or oil central heating or solid-fuel stoves are used to heat homes |
Give 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 |
What 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 |
What 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 |
How does aluminium foil between a radiator and the wall reduce the rate of energy transfer? | it reflects radiation away from the wall |
How 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 |
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