I have to support why we were told to neglect friction during a physics lab test

Question

I have to support why we were told to neglect friction during a physics lab testing newtons second law. We used an air track and air cart with a weighted mass on the end of a string conecting cart to mass through a pulley system. I was asked to support this with percent error values, I attached my table, but am having a hard time understanding how to support the neglect of friction with a percentage error.

MY MAIN QUESTION - why is it okay to neglect friction in this experiment, how can I support this decision via percent errors.

m, (kg) 0.000983 0.001966 0.002949 0.003932 0.004915 0.005898 #Of clips | t(sec) |Tension (N) | a(m/s) 2 3.79 0.01908996 0.097 3.17 10.02848981| 0.139 2.61 0.03779486 0.206 2.22 10.047006531 0.284 2.11 0.056126230.314

Explanation / Answer

percentage error = {m2 * (g+a) - T } *100 /(m2 * (g+a))

where T = tension and g= acc.due to gravity = 9.81 m/s2

1 percentage error = {0.000983*(9.81+.043) - 0.00959385}*100/{0.000983*(9.81+.043)} = 0.94624 %

2  percentage error = 1.45 %

3  percentage error = 1.95 %

4  percentage error = 2.44%.

5  percentage error = 2.93%

6  percentage error = 3.418 %.

since the errors are very small which account the friction, hence frictional force can be neglected.

note: the point which you might have missed is the force due to gravity on the mass.

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