Re: [Phys-l] Data Analysis Questions

[ludwik kowalski <kowalskil@mail.montclair.edu>]

On Nov 26, 2008, at 8:59 AM, Julie Quah wrote:

> Hey folks,
>
> I am looking for some data to create data analysis questions,  
> particularly
> in the topics on wave, sound and optics. Any resource offerred will  
> be much
> appreciated.

Here is a possible activity. Consider the thin lens formula 1/s + 1/s'  
= 1/f . It offers a possibility for calculating f from the known  
values of s and s'.

You need an optical bench (or something equivalent), a source of light  
and a white screen to observe the real image. Position the source at a  
known distance from the lens (s) and ask students to measure s'. The  
results will fluctuate because it is difficult to decide where the  
image is the most sharp. This will generate data for calculating the  
mean value and the standard deviation. Do not tell students what the  
true value of f is till the reports are submitted.

Suppose f=100 mm and s=150 mm. The expected s' is 300 mm. The actually  
reported values of s' will fluctuate considerably. Suppose it is a  
classroom activity with a single setup. Then invite students to come  
and measure the s'. Each student should write the result on a piece of  
paper. Collect the reported results and analyze them. That offers a  
chance to discuss significance of standard deviation.

Similar activity can be conducted by using a standing wave apparatus.


Ludwik Kowalski, a retired physics teacher
5 Horizon Road, Apt. 2702, Fort Lee, NJ, 07024, USA
Also an amateur journalist at http://csam.montclair.edu/~kowalski/cf/