Please enable JavaScript.
Coggle requires JavaScript to display documents.
physics unit 1: energy - Coggle Diagram
physics unit 1: energy
-
-
-
-
specific heat capacity.
internal energy is the total kinetic and potential energy of all the particles that make up a system. doing work on a system increases the energy stored in a system. heating changes the energy stored in a system by increasing he energy of particles within it. as the energy increases this will either increase the temperature or produce a chnage of state. if the temperature increases the increase depends on:
- the mass of the substance heated.
- what the substance is
- the energy input.
specific heat capacity of a substance is the amount of energy required t raise the temperature of one kilogram of the substance by one degree Celsius.
-
required practical
- set up the apperatus.
- measure the start temperature.
- switch on the electric heater for one min.
- measure the end temperature
- measure the voltage and current to find the power
- repeat for different liquids.
7.calculate the specific heat capacity.
independent variable: type of liquid
dependant: the temperature.
Control variables: amount of liquid used and energy provided.
energy transfers.
energy can be transferred usefully stored or dissipated. in a closed system total energy never changes but is still transferred from one store to another.
e.g when an electricity powered lift raises the carriage: - it transfers electrical energy into gravitational potential energy.
- some energy is dissipated into the surroundings as heat and vibrational (sound) energy.
unwanted transfers reduce by:
- lubrication: reduces the friction that produces heat.
- tightening any loose parts: prevents unwanted vibration that wastes energy as sound
- thermal insulation: reduces heat loss.
required practical
- take four test tubes and wrap each one with a different type of insulation
- fill each test tube with hot water and measure the start temperature of each one.
- start the stopwatch and record the temperature every minute for 10 minutes.
- plot the results on a graph of time against temperature.
independent: type of insulation. dependant: temperature. control variables: times at which temperature is measured, volume of water in each test tube, and thickness of insulating material.
-