Formulas

• Speed

  Distance / time
• Acceleration

  Change in velocity / time
• Current in series


  All the same
• Current in parallel


  Adds up to a total of the circuit
• Voltage in series & parallel


  Adds up to total circuit voltage
• Speed from distance-time graph


  Gradient
• Gravitational field strength

  Weight / Mass
• Pressure


  Force / Area
• Pressure in fluid


  Density x GFS x Height
• Weight

  Mass x GFS
• Density

  Mass / Volume
• Volume

  Mass / Density
• Constant speed


  No resultant force on moving object
• Force

  Mass x Acceleration
• Resultant Force

  Change in momentum / Change in time
• Circular motion


  Resultant force towards the centre

  Changing velocity

  Accelerate
• Spring constant

  Force / Extension
• Moment


  Force x Perpendicular distance from Pivot
• Equilibrium

  No resultant force and no resultant moment
• Momentum


  Mass x Velocity
• Impulse


  Force x Time
• Impulse


  Change in momentum
• Hooke's law


  F = constant x extension
• Kinetic energy


  1/2 x Mass x Velocity ^ 2
• Change in gravitational potential energy

  Mass x GFS x difference in height
• Work done


  Force x Distance moved
• Work done

  Change in Energy
• Power

  Change in energy / Time
• Power

  Work / Time
• Efficiency %

  (Useful output / Total input) x 100
• Boyle's Law

  P1 V1 = P2 V2

  Constant temperature
• Specific Heat capacity


  Energy / (Mass x Change in Temperature)
• Thermal Capacity

  Specific Heat Capacity x Mass
• Transverse waves


  Electromagnetic

  Seismic

  Light waves
• Longitudinal waves


  Sounds wave

  Ultrasound

  Seismic P
• Wave speed

  Wavelength x Frequency
• Refractive index

  n = sin i / sin r
• Total internal reflection


  The angle of incidence > Critical angle
• Critical angle


  n = 1/sin (c)
• Radiowaves -> Gamma rays

  Increase frequency

  Decrease wavelength