How does mass affect acceleration?

[conspicuous]

Homework Statement

Hello all. I performed an experiment in Physics class to attempt to answer the following question:

How will changing the mass of a trolley affect its acceleration when it goes down the slope?

I changed the mass of a trolley on each trial, let it go down a slope, and measured its acceleration. I added a total of 50 grams to the trolley but the acceleration always remained constant. I am perplexed as to how this happened.

Variables:

• Dependent (measured): acceleration
• Independent (being changed): mass of trolley
• Controlled (kept stable): angle of slope and distance traveled

Homework Equations

F = ma

The Attempt at a Solution

Newton's Second Law states that mass and acceleration are inversely related (i.e, if mass increases, acceleration should increase), but such case did not happen. How did it not?

 

[Filip Larsen]

Welcome to PF!

What force (F) do primarily work on the trolley when it accelerates down the slope? Perhaps you can write up an equation for F and equate that to ma and see if there is something you can reduce away.