Lesson 10.4 • Competencies 10.1, 10.2 & 10.3Interactive Simulation

Mechanical Properties of Matter Practicals Hub

Complete interactive investigations for all 4 official NIE A/L Physics syllabus practicals: Searle’s wire Young’s modulus (Exp 14), Stokes’ falling sphere viscosity (Exp 15), Capillary tube surface tension (Exp 16), and Microscope slide surface tension (Exp 17).

Marking a lesson complete represents finishing your study of the topic; it does not denote tested mastery.

Learning Objectives

Perform virtual experiments with live data tables, graph plotting, and gradient analysis.
Apply official precautions, eliminate zero and backlash errors, and assess experimental uncertainties.

Syllabus Topic Outline

Competencies 10.1, 10.2 & 10.3

1Experiment 14: Searle’s Young’s modulus apparatus and spirit level leveling
2Experiment 15: Stokes’ falling sphere viscometer and terminal velocity timing
3Experiment 16: Capillary rise and travelling microscope meniscus measurement
4Experiment 17: Microscope glass slide pull-off force method

A/L Physics Laboratory: Unit 10 Mechanical Properties Practicals Hub

Official NIE A/L Physics Practical Handbook Investigations (Experiments 38, 39, 40, 41, 42): Searle’s apparatus, Poiseuille & Stokes viscosity, glass slide, capillary rise, and Jaeger’s maximum bubble pressure.

Determination of Young's Modulus of a Metal Wire using Searle's Apparatus (Exp 14)

Physical Principle & Governing Equations

Within Hooke's elastic limit: Y = (F L) / (A e) = (4 M g L) / (π d² e). From a plot of extension e versus load mass M, gradient m = e / M. Then Y = (4 g L) / (π d² m).

Y = (4 g L) / (π d² · slope)

Required Laboratory Apparatus

Searle's apparatus with spirit level & spherometer/micrometer, identical reference and test wires, slotted masses (0.5 kg increments), micrometer screw gauge, meter ruler.

Experimental Observations & Data Table (L = 2.8 m, d = 0.56 mm)

Load M (kg)	Micrometer Reading (mm)	Extension e (mm)	Calculated Stress (MPa)
1.0	0.18	0.18	39.8
2.0	0.36	0.36	79.6
3.0	0.55	0.55	119.4
4.0	0.73	0.73	159.2
5.0	0.91	0.91	198.9

Derived Experimental Result:

Slope Δe / ΔM ≈ 0.182 mm/kg = 1.82 × 10⁻⁴ m/kg.
Y = [4 × 9.8 × 2.8] / [π × (0.56 × 10⁻³)² × 1.82 × 10⁻⁴] ≈ 2.01 × 10¹¹ Pa = 201 GPa (Consistent with structural steel wire).