recall grids

• two energies that transfer as waves

  light energy

  sound energy
• what is needed to create a wave?

  vibration
• what is a wave?

  waves are vibrations that transfer energy
• waves transfer energy not matter
• transverse waves

  the vibration perpendicular to the fraction of the energy transfer to the wave
• longitude wave

  vibrations are parallel to the direction of energy transferred of the wave
• transverse wave parts

  peak

  trough

  amplitude

  length

  equilibrium line
• longitude waves parts

  oscillation

  compression

  wavelength

  rarefaction
• what is transferred to generate static?


  electrons
• when is static electricity dangerous?

  high concentration of co2

  around flammable gasses
• unit for volts?

  amps (A)
• units for potential difference?

  volts (V)
• equation for potential difference?

  current x resistance
• equation for pd?

  energy transfer / charge
• what causes resistance in a wire?

  ions cause electrons to collide, loosing energy which causes resistance
• why is a resistor an ohmic conductor?

  it has a constant resistance
• what is a ohmic conductor?

   a conductor that follows Ohm's Law, maintaining a constant resistance over a wide range of voltages.
• what is resistance?

  anything that slows down the current
• equation that links charge, current and time?

  current = charge / time
• what is the pd for mains electriciy?

  230v
• what is the frequency for mains electricty?

  50Hz
• what causes for a fuse to blow?

  if the current gets too high
• name the 3 wires in a plug?

  live

  earth

  neutral
• describe the meaning of a movement of force?

  turning effect of a force
• describe the meaning of the center of mass?

  where all the mass is concentrated
• what is a vector?

  a quantity with size and direction
• what is a scalar?

  a quantity with only scale
• force - newtons

  mass - kilograms

  time - seconds

  energy - joules
• newtons first law

  an object will say at rest or move at a constant speed unless acted on by a resultant force
• what is meant by terminal velocity

  the maximum constant speed that an object can reach when its forward force prevents further acceleration
• what is a system?

  an object or a group of objects
• define terminal velocity?

  the max velocity an object can reach for the current resistance forces
• speed equation?


  speed = time / distance
• what is amplitude?

  amplitude - the maximum displacement of a point of a wave from its rest position
• what is frequency?

  Frequency is the number of waves that pass a given point in one second
• 2 types of errors

  systematic

  random#
• what is a parallax error?

  not reading results at a suitable eye level
• what is a zero error?

  an error that is made because of a power of ten error
• uncertainty is half the range of random errors
• all electromagnetic waves travel at 300 million m/s in the air