Thermal energy Flashcards
(15 cards)
What is a system?
A system is an object or group of objects.
How can energy transfers take place?
Energy transfers happen due to forces doing work, heating, electrical flow, light radiation and sound waves.
What is internal energy?
Internal energy is total kinetic and potential energy of all the particles that make up a system.
When an object is heated what happens to it’s internal energy?
When an object is heated it’s internal energy increases and it will either increase in temperature or change state.
How does the temperature of a gas relate to the kinetic energy of a gas?
When the temperature of a gas increases, the average kinetic energy of the molecules also increase.
What is specific heat capacity?
The specific heat capacity of a substance is the amount of energy required increase 1kg of that subtance by 1 degree.
How do you measure the specific heat capacity of a substance accurately?
The mass of the metal block is measured using a balance.
The immersion heater is connected to a power supply and transfers energy to the block, this energy is measured using a joulemeter. The `insulation reduces the amount of energy that is transferred to the surroundings, this reduces
uncertainty in the value for the specific heat capacity.
What is accurate data?
Accurate data is data close to the true value.
What is precise data?
Precise data is data which has little spread between measurements.
What is reproducable data?
If a different person can produce the same result with the same method and equipment then the data is reproducable.
What is repeatable data?
If the same person can produce the same results with the same method and equipment then the data is repeatable.
What is systematic uncertainty?
Systematic uncertainty is when a measurement is always too high or too low usually because of an error in the equipment.
What is a zero error?
A zero error is an error when a measuring instrument reads a value when it should say zero.
What factors affect the rate of cooling of a building?
The thickness of the walls and the thermal conductivity and insulation affect the cooling rate of a building.
What is specific latent heat?
Specific latent heat is the amount of energy required to change the state of 1kg of a substance with no change in the temperature.
