P1a Heating houses Flashcards
Why does the rate of cooling for warm bodies (objects) depend on the temperature difference compared to the surroundings?
The temperature difference compared to the surroundings. The greater the difference in temperature, the faster the rate of cooling will be. For example, a hot cup will cool down quicker in a cold room than in a warm room.
What are the consequences of direction of energy flow between bodies of different temperatures?
The consequences of the direction of energy flow between materials of different temperatures are that energy tends to flow from hot objects to cooler ones. For example, warm radiators heat the cold air in your room because heat flows.
What is temperature?
Temperature is a measure of hotness on an arbitrary or chosen scale/a measure of the average kinetic energy of the particles in a substance. The hotter something is, the higher its temperature and the higher the average KE of its particles.
What is temperature represented by?
It is represented by colour in a thermogram.
How can colours be represented by a range of colours on a thermogram?
Hottest parts:white/yellow/red.
Coolest parts:black/dark blue/purple.
What is heat a measurement of?
It is a measurement of energy.
What is heat measured ?
It is measured in Joules (J).
What is heat?
Heat is a measurement of energy on an absolute scale.
What is the energy needed to change the temperature of a body (object)?
The energy needed to change the temperature of a material depends on mass, the material form which it is made and the temperature change. For example, you need 4200J to heat 1kg of water by 1 degree celsius, but only 139J to heat 1kg of mercury by 1 degree celsius.
What is specific heat capacity?
The specific heat capacity of a substance is the amount of energy needed to change the temperature of 1 kg of the substance by 1°C.
What is the equation for Specific Heat Capacity?
energy=massSHCtemperature change
What is specific latent heat?
The specific latent heat of a substance is a measure of how much heat energy is needed to melt or boil it. It is the energy needed to melt or boil 1 kg of the substance.
What is the equation for specific latent heat?
energy=mass*specific latent heat
How is energy still being transferred even though there is no temperature change when materials are boiling, melting or freezing?
A substance must absorb heat energy so that it can melt or boil. The temperature of the substance does not change during melting, boiling or freezing, even though energy is still being transferred.
