# Homework Help: Some Help With My Ticker-Timer Experiment

1. Oct 14, 2009

1. The problem statement, all variables and given/known data

Hi, I recently preformed a ticker timer experiment in my grade 11 physics class, and I seem to be having a bit of trouble with the assignment.

Our results were recorded as follows.

Time (s)|Distance (cm)
0|0
0.1|6.15
0.2|21.35
0.3|43.15
0.4|71.55

I am supposed to create a d-t graph which I have done, and then create a v-t graph and a-t graph. I am having troubles getting from the d-t graph to the v-t graph. I am aware of using the tangents of each points, but I cannot seem to do this correctly, as my results are always incorrect. So I need to find a way to find the instantaneous velocity for each time segment, that way I can plot the v-t graph.

2. Relevant equations

I am not positive which equations can be used, other than the tangent method, but as I previously stated, I am doing this incorrectly and would greatly prefer an equation (if possible) for the instantaneous speed.

3. The attempt at a solution

I have tried finding the instantaneous velocity by using v = d/t (for example, v = 6.15/.1) but this does not work either because when plotted, the graph is always a curve.

Also, if I were to calculate the acceleration from my results. Would I calculate the average velocity, then divide that by t2 - t1?

Thanks for any help, it is greatly appreciated. Also, I am sorry if I used the template incorrectly, this is my first time posting here.

2. Oct 14, 2009

### rl.bhat

Hi Adam SE, welcome to PF.
You have to draw the tangent at every point very accurately to get the correct v-t graph.
If you are able to post, do so.

3. Oct 14, 2009

Thank you for the response, it is appreciated.

A problem I am having is accuracy, but the biggest problem I have is knowing when to stop the tangent. Do I stop it at the next time segment/axis, or do I stop it until it is enough to measure?