Error propagation for value not directly measurable

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sunrah
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Homework Statement


This should be very simple:
Given the following (boundary frequency for photoelectric effect):

[itex]\nu = \frac{\phi}{h}[/itex]

what would be the error on [itex]\nu[/itex]?

Homework Equations


The Attempt at a Solution



[itex]\varphi[/itex] and h are both determined through linear regression (y = mx + c). Where

h =em and [itex]\varphi = -ec[/itex]. The errors on m and c are supplied courtesy of computer software.

My understanding is that the product/division rule for error propagation can be used:

[itex]\delta \nu = \nu\sqrt{(\frac{\delta \varphi}{\varphi})^{2}+(\frac{\delta h}{h})^{2}}[/itex]

my instructor disagrees
 
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well, i spoke to her now and she says that the systematic error on the voltage (digital multimeter) should be included.

[itex]eU = h\nu + \varphi[/itex] (1)

where [itex]\varphi[/itex]is the work function.
The boundary frequency is given as [itex]\nu_{b} = \frac{\varphi}{h}[/itex] (2)

Of course we can write the [itex]\nu_{b}[/itex] in terms of voltage using (1), but we determined [itex]\varphi[/itex] and [itex]h[/itex] using linear regression which also supplied the standard error on those values. I'm not really sure how to determine the errors on [itex]\nu_{b}[/itex] now. Should I ignore the error on [itex]\varphi[/itex], combine (1) and (2) and just use the error for the voltage provided by the multimeter manufacturer?

[itex]\delta \nu_{b} = \nu_{b} \sqrt{(\frac{\delta h}{h})^2 + (\frac{\delta U}{U})^2}[/itex]