# Homework Help: Centripetal force experiment

1. Oct 3, 2015

### andyfeynman

1. The problem statement, all variables and given/known data
I'm doing the lab report questions for the centripetal force experiment using this apparatus: ftp://ftp.pasco.com/Support/Documents/english/ME/ME-8088/012-08478B.pdf.

One of the lab questions asks whether using a larger "free mass" reduces the percentage error.

2. Relevant equations
F=Mω2R

3. The attempt at a solution
I think there are three main sources of error:
1. there is friction between the "free mass" and the rotating arm as it may not completely free to slide along the groove.
2. the cable may not be completely vertical. Therefore the force sensor may measure an extra horizontal component of the tension.
3. the pulley is not frictionless and it has a rotational inertia

Then I guess it won't because a larger mass implies greater friction between the mass and the rotating arm, hence larger error. But I'm not really sure...

2. Oct 3, 2015

### Staff: Mentor

The purpose of the lab report is for you to take your best shot at the answers. I recommend that you have a little confidence and say what you think. It sounds like you've done a pretty good job so far.

Chet