Physics - Chapter 1 Flashcards
Name the different types of energy stores
Gravitational potential energy
Kinetic energy
Elastic potential energy
Thermal (heat) energy
What physical processes cause the transfer of energy between different energy stores
Mechanical (forces, sound waves)
Electric current
Electromagnetic waves
Heating
What happens in all energy transfers eventually?
Dissipated to heat in the surroundings
Pendulum
(GPE - KE - GPE)
Car at constant speed
(Chemical - thermal energy)
Car braking
(Kinetic ➡️ thermal energy)
Gravitational potential energy equation
Mass X gravity X height
Kinetic energy equation
0.5 X mass X velocity squared
Elastic potential energy equation
0.5 X Spring constant X extension squared
Energy equation
Mass X specific heat capacity X temp change
What is thermal conductivity a measure of?
How quickly thermal energy is passed through a substance by conduction
How can buildings be designed to have a Lower conductivity
Have thicker walls
The equation to calculate payback time
Payback time (years) = cost of installation (£) divided by savings per year in fuel costs (£)
One advantage and disadvantage of coal as an energy source
Pro - Relatively cheap to mine
Con - non renewable
One advantage and one disadvantage of oil as an energy source
Pro - short start up time
Con - non renewable
One advantage and one disadvantage of nuclear power as an energy source
Pro - produces lots of energy
Con - produced dangerous waste
One advantage and one disadvantage of wind as an energy source
Pro - renewable
Con - no wind sometimes
One advantage and one disadvantage of hydroelectric energy
Pro - renewable
Con - can flood areas
One advantage and one disadvantage of solar energy as an energy source
Pro - renewable
Con - no sun at night
One advantage and one disadvantage of Geothermal energy as an energy source
Pro - renewable
Con - only available in volcanic regions
What happens to something if it gains electrons
It becomes negatively charged
What happens if something looses electrons
It becomes positively charged
In electric fields what do the arrows show?
The way a positive charge would move
What is the current?
The rate of flow of charge
What is potential difference?
The energy transferred by one coulomb of charge
What is resistance?
A measure of how much a component reduces the current passing through it
Potential difference equation
Current X resistance
What happens to something if it gains electrons
It becomes negatively charged
What happens if something looses electrons
It becomes positively charged
In electric fields what do the arrows show?
The way a positive charge would move
What is the current?
The rate of flow of charge
What is potential difference?
The energy transferred by one coulomb of charge
What is resistance?
A measure of how much a component reduces the current passing through it
Potential difference equation
Current X resistance
What happens to the current in a series circuit?
It’s the same everywhere
What happens to the current in parallel circuits?
Shared between the different routes
What happens to the potential difference in a series circuit?
Shared between components
What happens with the potential difference in a parallel circuit?
Same across each different route
What happens with the resistance in a series circuit?
Resistances add together
What happens with the resistance in a parallel circuit?
Total resistance is Lower than the individuals resistors
What colour is the earth wire and what does it do?
Green and yellow - if there is a fault and the case becomes live the current passes along this wire making the device safe
What colour is the neutral wire and what does it do?
Blue - this wire completes the circuit and has a p.d. Of 0V
What colour is the live wire and what does it do?
Brown - provides energy to the device, potential difference of 230V
What does a fuse do?
If too much current goes through then the wire melts this breaks the circuit and stops the current
How does an RCCB circuit breaker work?
It breaks the circuit if there is a difference between the current in the live and neutral wires
Internal energy equation
Potential energy + kinetic energy
What is alpha radiation?
2 protons
2 neutrons
What is beta radiation?
An electron from the nucleus
What is gamma radiation?
em wave
What is alpha radiations range in the air?
Up to 5 cm
What is beta radiations range in the air?
Up to 1m
What is gamma radiations range in the air?
A long way
What is alpha radiation absorbed by?
Paper
What is beta radiation absorbed by?
A few mm of aluminium
What is gamma radiation absorbed by?
Thick lead
How ionising is Alpha radiation?
Very ionising
How ionising is beta radiation?
Quite ionising
How ionising is gamma radiation?
Weakly ionising
