3 ms·

How do ±6.4 and ±6.9 combine to ±9.4 and not ±13.3 ?

• pif 5y ago
  https://physics.nist.gov/cuu/Uncertainty/combination.html https://physics.nist.gov/cuu/Uncertainty/combination.html
• fulvioterzapi 5y ago
  Errors do not sum like regular numbers. You want to take the square root of the sum of the squares of the errors. sqrt(6.4^2 + 6.9^2) ≈ 9.4 You can have a look here: http://ipl.physics.harvard.edu/wp-uploads/2013/03/PS3_Error_Propagation_sp13.pdf http://ipl.physics.harvard.edu/wp-uploads/2013/03/PS3_Error_...
  • stocknoob 5y ago
    That PDF is great, thanks for sharing.
• alephxyz 5y ago
  The variances are additive but not the std dev. Sqrt(6.4^2 + 6.9^2) = 9.4
• deleted 5y ago
  [deleted]