measurements and their errors

• what are si units

  the fundamental base units of physical quantites
• what are the 6 si base units 


  kg, m, A, k, mol, s
• derive the si units for energy

  1/2 m v^2 = kg x m/s x m/s = kgm^2/s^2
• what is femto

  10^-15
• what is giga's prfeix

  10^9
• what is 1eV in J

  1.6x10^-19 J
• what is the prefix for pico

  10^-12
• a random error effects the precision of and cannot be completely removed it causes differences in measurements
• a systematic error affects accuracy and occurs due to faults in the equipment/method causing the result to differ from the real value by the same amount each time
• how can you reduce random errors

  take 3 repeats nad calculate the mean

  use a data logger

  use equipment with a higher resolution
• define resolution

  the smallest value that can be measured