# Partial derivative help

1. Jun 16, 2005

can anyone verify that the equations on the following page, http://nsr.f2o.org/equations.htm [Broken] are corretly solved. The equations are used to find the uncertainity in the calculation of acceleration in my physics lab. The uncertinty (delta a) would be the sum of all of the four equations, which appear correct.

However, the last equation, solves for the uncertainty in g (delta g) which is gravity...I'm not sure how should I solve it using partial derivatives, on the bottom it has what h_21 and x_12 should be...any help would be much appreciated..thank you!

Last edited by a moderator: May 2, 2017
2. Jun 16, 2005

### OlderDan

What did you do in your lab to measure g? It sort of looks like you made two position measurements and two velocity measurements, with some uncertainty. There must be some time interval involved. Is there a time interval uncertainty? How is "a" different from "g"? Is not your calculated "a" an estimate of "g"?

3. Jun 16, 2005

People see the pdf of the lab, the equation is on last page (pg 10) Thank you! http://nsr.f2o.org/exp2.pdf [Broken]

Last edited by a moderator: May 2, 2017
4. Jun 16, 2005

### OlderDan

The first four dequations in your original note attachement come from taking partial derivatives of equation 2-7 in the write-up. The first two are wrong. What is

$$\frac{d}{dx}x^2$$

You have not done the derivatives for your Equation 5. They come from equation 2-5 in the write-up

Last edited by a moderator: May 2, 2017