# Thread: Hey All fisrt post

1. ## Hey All fisrt post

Hey all

this is my first post and i am trying to find a formula (a bit rusty on math since school) i cant seem to track down. I am wondering if someone could provide any help.

I am looking to measure the rate of decelartion of a wheel, this will be slow but will be non constant.

so i think that i am looking for the differntail equation for angular acceleration.

all help would be greatly appreicate

2. Originally Posted by erdnase
Hey all

this is my first post and i am trying to find a formula (a bit rusty on math since school) i cant seem to track down. I am wondering if someone could provide any help.

I am looking to measure the rate of decelartion of a wheel, this will be slow but will be non constant.

so i think that i am looking for the differntail equation for angular acceleration.

all help would be greatly appreicate
You can't do this without data from the wheel and knowledge of what kind of relationship the angular acceleration has with time. Do you have a specific example in mind?

-Dan

3. hey all

thanks for the information.

I have collected sum data and was wonder if you could porvide furhter help with the forumla for find the speed and accelartion of a wheel

1revoultion 5.4 seconds
2 rev 5.4
3 rev 5.5
4 rev 5.5
5 rev 5.6

From this data is it posible to find the rotational speed in seconds and the deccealration.

is this a standard forumla for this calculation or is dependable on the data collected?

4. Originally Posted by erdnase
hey all

thanks for the information.

I have collected sum data and was wonder if you could porvide furhter help with the forumla for find the speed and accelartion of a wheel

1revoultion 5.4 seconds
2 rev 5.4
3 rev 5.5
4 rev 5.5
5 rev 5.6

From this data is it posible to find the rotational speed in seconds and the deccealration.

is this a standard forumla for this calculation or is dependable on the data collected?

$\omega = \omega _0 + \alpha t$
where $\alpha$ is your average. Otherwise you are looking for a technique to do a numerical derivative from your angular speed data. Hope it helps!