# WEIGHTED MEAN - For averaging data w pre

```Phys 415 Assignment
1) For a particle of mass m falling under the influence of gravity and experiencing a drag
force F = bv 2, deterimine the velocity v(t). Make a graph v(t) vs t. Label the axis.
2) Write a short one page essay on the Franck Hertz Experiment.
3) Determine the series of energy jumps in Hg by the Franck-Hertz technique. Use
measurements in text Figure 1-10. Average your values to determine a mean enegy jump
in Hg (average &plusmn; rms please)
Explain which transition (Hg Spectrum) is being observed.
4) Sketch the energy level configuration for the Na atom and explain the Na doublet.
What is the energy jump for the Franck-Hertz experiment in Na?
WEIGHTED!!MEAN - For averaging data w pre-determined errors.
! x !w
i
x!= !
i
i=1,N
! !w
!!!!!w i ! &quot; weights or probabilities!
i
i=1,N
i Given!data!!x i &plusmn;# i !!we!can!choose!w i =!1/# i 2 !, thus the rms errors on x i give the
weight on each measurement.
i One might choose the weights from apriori knowledge (Bayesian logic).
5)! Determine x!if!!!w i =!c!!!!(constant).
```