Acceleration decrease on inclined air track

[kiyoshi7]

Hello, I have a cart going down an air track with an inclination of 7 ° and for some reason my acceleration is going on a downward trend, my velocity is increasing and naturally so is the time. to find velocity I'm using v = (2x)/t and for acceleration I'm using a = (2x) / (t^2). Can you tell mr what I'm doing wrong or what I'm missing?

I'm sorry if I'm not being clear if you want I can put the data up for you guys to see.

Thank you for your help.

 

[jbriggs444]

Hello, I have a cart going down an air track with an inclination of 7 ° and for some reason my acceleration is going on a downward trend, my velocity is increasing and naturally so is the time.

So you are plotting acceleration versus time, expecting it to be constant and finding that instead it is trending downward. What result would you expect if air resistance were non-negligible?