Speed, Displacement, and Velocity

• DISPLACEMENT

  distance in a given direction
• VELOCITY

  rate of change of displacement with respect to time
• CONSTANT VELOCITY

  • moves in straight line
  • does not speed up or slow down
• (MANDATORY EXPERIMENT) MEASURING CONSTANT VELOCITY USING AN AIR TRACK

  • glider and card, air track, light gates, blower
  • air track should be level to ensure constant velocity
  • the scalar timer records the time it takes for the card to pass through, therefore we must measure the length of the card
  • use formula velocity = displacement/time
• (MANDATORY EXPERIMENT) MEASURING CONSTANT ACCELERATION USING AN AIR TRACK

  • the air track should be level with weights attached to the glider by a string to allow for constant acceleration
  • the scalar timer records the time it takes for the card to pass through, therefore we must measure the length of the card
  • also must measure distance between time gates
  • calculate velocity first
  • then use vusat tables
• ON A VELOCITY TIME GRAPH

  • slope = acceleration
  • area under graph = distance travelled
• (MANDATORY EXPERIMENT) MEASUREMENT OF "g" BY FREE FALL

  • set apparatus as shown in diagram (circuit)
  • release mechanism
  • measure displacement (s)
  • record time (t)
  • PRECAUTIONS
  • avoid parallax
  • measure from bottom of ball to top of trapdoor
  • use heavy small ball to avoid air resistance
  • there can be a delay on the timer when the ball is dropped, so repeat exp 3/4 times and use the shortest time