(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

the mass of a particular sample of rock retrived from Mars is m=772.2+or-0.2g. The sample is in the shape of cylinder of height h=10+or-0.1 cm and base radius r=2.5 +or-0.1cm. calculate the density of the rock sample in units of kg/m^3. You must state your result in the correct units with its associated uncertainty. The volume of a cylinder is V=pir^2h.

2. Relevant equations

p=m/v

3. The attempt at a solution

I can get the density but I cannot get the correct uncertainty.

The density I get is

(772.2g/196.35cm^3)((1 kg/m^3)/10^-3g/cm^3)=3932.77 kg/m^3

I believe the uncertainty is supposed to be +or-400 but I end up with four.

(delta p)/(3.9g/cm^3) = .2/772.2 + .14/196.35

delta p = .004 g/cm^3

.004 g/cm^3 ((1kg/m^3)/(10^-3 g/cm^3) = 4 kg/m^3

Im new to this propagation of errors stuff. Using sig figs other people in my class got either 4000 +or- 400(or +or- 100) I cant remember.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Propagaton of errors

**Physics Forums | Science Articles, Homework Help, Discussion**