How do you compound error for physics A2 coursework? - Answers

If plotting a graph and are producing a straight line to find a gradient: You plot a line of best fit, then you plot two other lines starting from the same point which show the extreme lines of best fit (do this in fainter lines so that the best one stands out). Find the gradients for all three lines, use the first line that you drew as the main value. Then find the largest difference between the middle line and the extreme lines E.g. if the gradient of the lines were: First line gradient = 1.2 Second (Top extreme line of best fit) gradient =1.5 Third (Minimum extreme line of best fit) gradient = 1.0 Find the larget difference: 1.5-1.2=0.3 1.0-1.2=-0.2 Therefore the largest difference is 0.3 (not 0.2) Therefore your final result would be: 1.2 (+-) 0.3 I hope this helps :D