Measure how a bar magnet changes the period of a small swinging magnet at different heights, then test the shift in a card's centre of gravity when masses are added. Paper 3 is done at the bench, so this page gives you a realistic set of readings for each experiment. Process them part by part, see how many of the 40 marks you would earn, then compare with a full-mark worked answer.
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Readings to the precision of the instrument (a metre rule to the nearest mm, a stopwatch time over several oscillations), repeated where needed, with enough values over a wide range (usually six).
Column headings with a quantity and its unit (for example T / s), raw readings to the same number of decimal places, calculated values to the right number of significant figures.
A graph with a sensible scale, crosses within half a small square, a line of best fit, a gradient from a large triangle and the y-intercept read or calculated, then the constants with units.
In Question 2: the percentage uncertainty in a reading, whether the results support a relationship, and four limitations each paired with a specific improvement.
The questions on this page are rephrased from a Cambridge International past paper for teaching. The readings, figures, wording of the workout and the worked answers are our own; the marking follows the published mark scheme. The original question paper is available from Cambridge.