Elasticity: Stress, Strain & Hooke's Law is one of 9 topics in the Grade 12 Technical Sciences CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Which formula correctly defines stress?
sigma = F/A
sigma = DeltaL/L0
sigma = E x epsilon only
sigma = ma
Answer: sigma = F/A — Stress (sigma) is defined as force per unit cross-sectional area, sigma = F/A.
Easy
2. What is the SI unit of stress?
Pascal (Pa)
Joule (J)
Newton (N)
No unit -- it is dimensionless
Answer: Pascal (Pa) — Stress is measured in pascals (Pa), equivalent to newtons per square metre (N.m^-2).
Medium
3. A force of 4000 N acts on a rod with a cross-sectional area of 0,002 m^2. Calculate the stress in the rod, in Pa.
Answer: 2000000 — sigma = F/A = 4000 / 0,002 = 2 000 000 Pa (2 x 10^6 Pa).
