Masses oscillating on springs keep coming back in 9702 Paper 3 Question 1. By hand, load the hanger, pull it down and let go, then time 10 oscillations with a real stopwatch. Tabulate T and T², plot T² against M and use the gradient to find the spring constant. Every attempt uses a different spring. The timing is real, so allow about 45 minutes.
Checked: Cambridge 9702 Paper 3, 2017 to 2019 and 2023 to 2025. Only the papers in our collection are listed, so the real number may be higher. Question papers are available from Cambridge.
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A stopwatch time for 10 oscillations with the right mass on the hanger, and T = t / 10.
Six sets over a wide range of M, headings with units (M in kg), every t to 0.01 s, and T² to the right significant figures.
Axes and scales, plotting, the line of best fit, a large gradient triangle and the y-intercept.
a and b from your own graph with units, k = 4π²/a in N m⁻¹, and the real limitation of the timing.
The marking follows the conventions in published Cambridge mark schemes. The experiments, readings and wording on this page are our own.