1. The problem statement, all variables and given/known data "From your graph, calculate the EMF and internal resistance of your cells. Include uncertainties in your calculations" Now I know how to work out the emf and int. resistance, but I am just not sure about how to incorporate uncertainties. 2. Relevant equations y = mx + c Vo = -rI + ε 3. The attempt at a solution Now the uncertainty for my Vo measurement is ±0.10V and current measurements is ±0.10A. the equation of the line is y = -0.12x +2.1 so the Int. resistance is 0.12ohms and the emf is 2.1V, but what are the uncertainties on these values???