Practical - Investigating reaction time

• What can speed up the reaction time and why?


  Caffeine because it is a drug
• • person`s arm should be resting on edge of table
  • hold a ruler vertically between their thumb and forefinger
  • make sure that the zero end of the ruler is level with their thumb and ginger
  • let go without warning
  • the person who is being tested should try to catch the ruler as quickly as they can
  • reaction time measured by the number on the ruler
  • repeat the test several time
  • calculate the mean distance that the ruler fell
  • then give the person to dring caffeinated dring and repeat the experiment after 10 minutes
• What are the control variables?


  • same person to catch the ruler each time
  • same hand to catch the ruler
  • ruler should be dropped from the same height each time
  • make sure that the person did not have any caffeine before the first experiment