RP3 determining g

• equipment:

  • stand
  • clamp
  • electromagnet
  • ball bearing
  • stopwatch
• method:

  • set up apparatus, make h = 0.5m
  • turn on electromagnet, attach ball bearing
  • set stopwatch to zero
  • switch off electromagnet, record time taken to fall on stopwatch
  • reduce h by 0.05m and repeat until h = 0.25m
  • repeat twice, record mean t for each h
• safety:

  • use a counterweight to stop the stand from falling over
• improvements:

  • distance between light gates must be kept constant so the speed at the second light gate is constant
  • cushion the ball bearing as it lands so that it doesn't fall onto anyone and hurt them
  • use a dense ball bearing to reduce the effect of air resistance
  • clamp the ruler directly next to the light gates to reduce parallax error