Work, Energy & Power 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. What is the SI unit of work?
Joule (J)
Newton (N)
Watt (W)
Newton-second (N.s)
Answer: Joule (J) — Work is measured in joules (J), the same unit used for all forms of energy.
Easy
2. A force acts perpendicular to an object's displacement. How much work does this force do?
Zero
Maximum possible work
Negative work
It depends only on the force magnitude
Answer: Zero — When force and displacement are perpendicular (theta = 90 degrees), cos(90 degrees) = 0, so W = FDeltacos(theta) = 0.
Medium
3. A 250 N force acts on a trolley over a displacement of 6 m in the same direction as the force. Calculate the work done, in J.
Answer: 1500 — W = FDeltacos(theta) = 250 x 6 x cos(0) = 1500 J.
