A level Physics Edexcel Paper 3 (EXAM) ELABORATION

g by free-fall method ANSWER : - Drop object using electromagnet - Measure time and distance - Use suvat to get g mnemonic for exam questions ANSWER : Syllables of experiment e = equation p = procedures i = improvements m = math analysis g by free-fall light gate vs stopwatch ANSWER : light gate prevents human reaction time random errors stop watches rely on human reaction time Light gates will have a smaller percentage uncertainty g by free-fall problems with air resistance ANSWER : Creates a systematic error as direction of air resistance will make value lower than true value g by free-fall graphical analysis ANSWER : put suvat equation into y = mx + c to get a straight line Gradient is useful as it takes less account of anomalies Resistivity of a metal method ANSWER : - Measure resistance of various lengths of wire - Measure diameter of the wire - Use equation to find resistivity Resistivity of a metal using a ohmmeter directly or using a voltmeter and ammeter ANSWER : Using a voltmeter and ammeter will provide better resolution however will create more uncertainty V/I = R Ohmmeters are quicker to measure Resistivity of a metal and the usefulness of a multimeter ANSWER : Allows to measure variable resolutions, allowing you to measure to the ideal 3 sig fig Systematic Errors in the Resistivity of a metal