Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have done a physics experiment (setup below). And was asked to determine the experimental and theoretical acceleration.

enter image description here

The data I've got

enter image description here

Ok, am I right to say

Experimental acceleration = $2(s_f - s_i) / t^2$

Theoratical acceleration = $m_2 \times 0.98 / m_1$


Percentage discrepancy = $\frac{|(Experimental - Theoretical)|}{Theoretical} \times 100$%

share|cite|improve this question
Hi Jiew - your question seems kind of unfocused. What concept is it specifically that is confusing you? Are you confused about why the mass of the cart affects its horizontal acceleration? Or are you confused about some step in the calculation of the theoretical acceleration? It would help a lot if you edit your question to focus on the one thing you want to ask. If you have multiple concepts to ask about, you can post more than one question about the same lab setup. – David Z Sep 27 '12 at 4:30
Ok, I edited my post and posted another question… – Jiew Meng Sep 27 '12 at 6:25
up vote 2 down vote accepted

If by $s_f$ and $s_i$ you mean the final and initial position, respectively --- so that $s_f-s_i$ is just $d$ in your table --- then yes, your experimental acceleration is right. As for your theoretical acceleration, it should be $\frac{9.8m_2}{m_1}$, not $0.98$ --- the acceleration due to gravity is $g=9.8$. I'm assuming you just made a typo. Your definition of percentage discrepancy is right.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.