# Chronograph physics project

1. May 1, 2006

### Freetempo

Well, hello im new here... i plan to stay here long and i seem too like the forum very much... Well i got a physics project and well i wanted to do it on chronograph(watches) i got full info. on the chronograph i just need to know how it's fuctions are related to physics using terminology...

well i hope someone could help me... thx

2. May 1, 2006

### Cyrus

Here is a start, an interesting (and important!) part of torsional springs is that it's motion is simple harmonic. This means that the angular frequency is given by $\omega = \sqrt { \frac{ \kappa}{I}}$. Since it is not a function of the amplitude, it means the watch won't run faster or slower as the amount of torsion in the spring decreases with time. Obviously not a problem in electronic watches today, but I use a watch that you have to wind up every so many hours to keep going. It uses a torsional spring too. They are nice watches, you don't get that "tick tick tick" sound with a battery powered watch.

Now, a REALLY interesting piece of work would be to figure out how they get the gears to work on the old spring chronographic watches to keep time and act as a stopwatch. (Here you have to relate the angular speeds of the meshed gears! to find the reduction/increase in gear speeds)

Also, keep in mind that offical stop watches used in the 60's cost hundreds if not thousands of dollars. If you used multiple stop watches to time something, you would get slightly different times from each watch. Now you can buy a \$10 watch from K-mart that is accurate to a hundreth of a second!

Last edited: May 1, 2006
3. May 2, 2006

### Freetempo

thx on tips man! by the way im looking like for a good summary or whatever.. that would explain me the function of a mechanic watch.. thx...