Thermal Energy Flashcards
System
A system is an object or group of objects
What are the various ways in which
energy can be stored in a system
Thermal store
Elastic store
Kinetic store
Gravitational store
Chemical store
Electrostatic store
Nuclear store
Magnetic store
How can energy transfers take place?
Energy transfers happen because of: forces doing work, a flow of an electrical current, heating, light radiation, and sound waves
What is internal energy?
It is the total kinetic and potential energy of all the particles that make up a system
What is potential energy?
Related to how far apart the molecules are.
When an object is heated what, happens to its internal energy?
When a substance is heated the energy transferred to it increases the internal energy of the system. This either raises the temperature of the system (increases the kinetic energy of the particles) or causes a change of state (increases the potential energy of the particles)
How is the temperature of a gas related to the average kinetic energy of its molecules?
The molecules of a gas are in constant random motion. As the temperature of a gas increases the average kinetic energy of the molecules also increases, this means the particles move around more quickly.
How can we 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.
Accurate data
close to the true value
Precise data
repeated measurements show very little spread around the mean
reproducible data
another person can get the same result with the same, or different method/equipment
repeatable data
same person can get the same results with the same equipment/method
random uncertainty
causes measurements to be spread around a mean value
systematic uncertainty
when measurement is always too high or too low for each repeat
zero error
when a measuring instrument reads a value and should say zero
