Average speed =
distance/time
Force =
mass x acceleration
Acceleration =
Change in velocity / time taken
Momentum =
Mass x Velocity
Density =
mass/volume
Work done
force x distance moved
Work done =
energy transferred
Kinetic Energy =
1/2 x mass x (speed)^2
Gravitational potential energy =
mass x gravitational field strength x height
Weight =
Mass x gravitational field strength
Gravitational field strength on earth
Assume its 10N/kg, but actually 9.81N/kg.
Pressure =
force/area
moment =
Force x perpendicular distance from pivot
Charge =
current x time
Voltage =
current x resistance
Electrical power =
current x voltage
Wave speed =
frequency x wavelength
Input(primary) voltage/ output(secondary) voltage
primary turns / secondary turns
n =
sin i / sin r
sin c =
1/n
Efficiency =
Useful energy output / total energy input x 100
Pressure difference =
height x density x gravitational field strength
Input power =
output power
Force =
Spring constant x extension
Increasing the voltage means
more current will flow
Increasing the resistance means
less current will flow
Current
Current is the rate of flow of charge round a circuit
Voltage
Voltage is the energy transferred per unit charge passed.
One volt
is one joule per coulomb
Energy transferred =
charge x voltage
Energy transferred =
charge x current x resistance
Live wire (Brown)
Alternates between a High+VE and -VE voltage of about 230V
Neutral Wire (Blue)
Neutral wire is always at 0V
Earth Wire (Green/Yellow)
For safety and work together.
Energy transferred =
current x voltage x time
Frequency =
1/time period
Transverse waves
In Transverse waves the vibrations are perpendicular to the direction the energy is transferred by the wave.
Longitudinal wave
In longitudinal waves the vibrations are parallel as the waves transfer energy.
angle of incidence =
angle of reflection
Principle of conservation of energy
Energy cannot be created or destroyed, it can only be transferred or stored
Conduction
Thermal conduction is the process where vibrating particles transfer energy from their kinetic energy store to the kinetic energy stores of neighbouring particles.
Convection
Convection occurs when the more energetic particles move from the hotter region to the cooler region and transfer energy as they do.
specific heat capacity
The energy required to raise the temperature of one gram of a substance by one degree Celsius
Energy required
mass x specific heat capacity x change in temperature
When a force moves an object through a distance...
Energy is transferred and work is done on the object
Power
Power is the rate at which energy is transferred
Energy lost from the gravitational potential energy store =
Energy gained in the kinetic energy store
Absolute zero
0 Kelvin or -273°C
Kelvin
Temperature in degrees Celsius -273
The temperature of a gas (in kelvins) is proportional to
the average energy in the kinetic energy stores of the particles.