Measurement: Paper 3 Guide (Form 4 SPM Physics)

Paper 3 at a glance

• Paper 3 carries 15 marks

Experiment: Simple pendulum, relating length to the period of oscillation

To investigate how the length of a simple pendulum affects its period of oscillation and to use the result to find g.

• Manipulated: Length of the pendulum, l
• Responding: Period of one complete oscillation, T
• Constant: Mass of the pendulum bob and the angle (amplitude) of swing
• Graph: Plot T² (y-axis) against l (x-axis). The points lie on a straight line passing through the origin, showing T² is directly proportional to l.
• Analysis: Since T = 2π√(l/g), squaring gives T² = (4π²/g) l. The gradient of the T²–l graph equals 4π²/g, so g = 4π² ÷ gradient.

• Full experiment page

Paper 3 skill checklist

• Table: quantities with units in the headings, consistent decimal places, derived column calculated correctly.
• Graph: axes labelled with unit, scale using more than half the grid, points plotted with a sharp pencil, best-fit line.
• Gradient: a large triangle on the line, coordinates shown, unit of the gradient stated.
• Relationship: "y increases linearly with x" or "y is directly proportional to x" only if the line passes through the origin.
• Precaution: one that improves accuracy, stated with its reason.

More on graph skills

• Graph skills hub
• All Paper 3 experiments

More Measurement resources

• Chapter overview: Measurement
• Revision Notes
• Common Mistakes
• Practice Questions
• Paper 2 Answering Guide
• Key Terms

Source: DSKP KSSM Physics Form 4 and 5 (Versi English), Sijil Pelajaran Malaysia: Format Pentaksiran mulai 2021, Fizik (4531) (Bahagian Pembangunan Kurikulum (BPK), KPM)