Finding the Mass from an Acceleration vs Force graph

AI Thread Summary
The discussion revolves around confirming Newton's second law through a track and trolley experiment, where the trolley's mass is constant at 752 grams plus additional weights. The participant plotted an acceleration versus force graph, yielding a slope of 2.6, leading to a calculated mass of 0.3846 kg based on the formula F=ma. However, this value significantly differs from the total measured mass of 787 grams, prompting confusion about potential errors in the experiment or calculations. The average acceleration was derived from five trials using a motion sensor to measure velocity over time. The conversation highlights the discrepancies between theoretical calculations and experimental results, indicating a need for further investigation into the methodology.
Crovati
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I have to confirm Newtons 2nd law via a track and trolley experiment

Homework Statement



The trolley’s mass is kept constant.
The weight of the cart (252g) plus two bar weights (500g) is = 752 grams, plus additional weights of either, 10g, 15g, 20g, 25g or 30g for the different trials.

The acceleration weights are:
25g
20g
15g
10g
5g
for the different trials.

This is what i got in the end...

Acceleration mass (g)--------Force (N)-----------Average acceleration ms-2

---------5-----------------------0.049---------------------0.10
---------10----------------------0.098---------------------0.22
---------15----------------------0.147---------------------0.36
---------20----------------------0.196---------------------0.44
---------25----------------------0.245---------------------0.63


Homework Equations



F=ma


The Attempt at a Solution



I plotted an acceleration vs Force graph, which gave me slope=2.6. And I thought that since F=ma, then the slope would be 1/m = 1/2.6 =0.3846... kg.
If i’m thinking correctly then this should be the value for the mass of the trolley (the cart+the bar weights+the additional weights+acceleration mass)

But when i add all of the components of the trolley’s mass i get 787g...which is nowhere near 0.3846... kg.

I’m not sure what i’m doing wrong, or if I’m going about solving this in completely the wrong way. Or maybe i made a big error during the experiment?
 
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Crovati said:
But when i add all of the components of the trolley’s mass i get 787g...which is nowhere near 0.3846... kg.

No, but it's pretty near 2 x 0.3836 kg. How did you get the acceleration?
 
MrAnchovy said:
No, but it's pretty near 2 x 0.3836 kg. How did you get the acceleration?
We used a motion sensor which took the velocity/time for each trial. the Average acceleration I posted there is the average of 5 trials for each of the different acceleration masses.
 
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