Physics307L F09:Schedule/Week 13 agenda/Error
- Recall when q = f(x) and we know x_best and sigma_x
- How about when q = f(x,y, ...) and uncertainties in more than one x, y are important?
- Let's derive
Key points after our derivation
- General formula is an approximation (small relative uncertainties)
- Usually written down to ignore covariance
General formula, uncorrelated uncertainties (From wikipedia)
Specific example, Millikan oil drop
Formulae for droplet charge (from John Callow):
Vf = fall velocity
Vr = rise velocity. These (along with others) can have comparable effects on q.