Units, Conversion Factors, Constants and Equations

Units

Work J

Power W or J/s

Force N or Kg m/s 2

Momentum N s or Kg m/s

Charge C

Speed m/s

Distance m

Time s

Area m 2

Volume m 3

Speed of Light, c 3x108 m/s 2

Electricity

Energy=Current*Voltage*time

Voltage=Current*Resistance


for resistors in series


for resistors in parallel


P=IV Power=Current*Voltage



In a plug, live is brown, neutral is blue and

earth is green/yellow.


C=np Cost=Number of units*Price per Unit.


The voltages around a circuit add up to the battery voltage.


Current into a junction=Current Out


Energy

GPE=mgh Gravitational Potential Energy=Mass*9.8*Height

KE=

E=Pt Energy=Power*Time

W=Fd Energy=Force*distance



Waves


speed=frequency*wavelength



Forces and Motion


Force=Mass*Acceleration

Momentum=Mass*Velocity

Weight=Mass*9.8

distance=speed*time

velocity=acceleration*time

Force=Pressure*Area