A solid cylindrical metal rod is analysed to determine its density
PHYSICS · Multi-part · A Level · Physics · Measurements and their errors · Measurements and their errors
Problem
A solid cylindrical metal rod is analysed to determine its density. The following direct measurements were recorded:
• Mass m=(125.0±0.1)g
• Length l=(20.00±0.05)cm
• Diameter d=(1.200±0.005)cm
(The rod is assumed perfectly uniform.)
(i) Calculate the volume of the rod and its absolute uncertainty.
(ii) Using the value obtained in part (i), determine the density of the rod with the correct number of significant figures and state the percentage uncertainty in the density.
(iii) By comparing the percentage uncertainties of the measured quantities, identify which single measurement contributes the greatest share to the overall percentage uncertainty in the density. Show your working.