End of year physics Collegiate Flashcards
What is something with high thermal conductivity
A good conductor
What is something with low thermal conductivity
A poor conductor or good insulator
Give examples of materials with high thermal conductivity
Most metals like copper, silver, gold, aluminium
Give examples of materials with low thermal conductivity
Plastic, wood, rubber, wool
Why are materials like wool good insulators?
They have a high amount of fibres which trap air and prevent convection
What happens in conduction?
A solid gains heat and the thermal energy travels down to colder areas by colliding with adjacent particles
What happens in convection?
Air or liquid particles gain heat and then rise to an area with less heat and are replaced by cooler particles
Define SHC
The specific heat capacity of a substance is the energy needed to raise the temperature of 1kg of the substance by 1*C
What is the formula for energy in SHC?
E=mc x theta
What does E or W stand for?
Energy transferred (work done)
What is E measured in?
J (Joules)
What does M stand for?
Mass
What is mass measured in?
Kg (kilograms)
What does C stand for?
Specific heat capacity
What is SHC measured in?
J/kg*C (Joules per kilogram degrees celcius)
What is Theta?
Change in temperature
What is Theta measured in?
*C (degrees centigrade)
What colour is best at emitting and absorbing radiation?
Black
What type of surface is best at emitting and absorbing radiation?
Matte
What colour is best at reflecting radiation?
White
What type of surface is best at reflecting radiation?
Shiny
The SHC of water is 4200 J/kgC. If I have 2kg of water and I heat it by 10C, how much energy would that take, in Joules?
84000 J
The SHC of water is 4200 J/kgC. If I heat it by 5C using 76kJ, how much water do I have, in kg? (Round to 2DP)
3.62 kg
What are the 7 stores of energy?
Kinetic, Thermal, Elastic potential, Gravitational potential, Chemical, Magnetic and electrostatic