Work, Energy & Power is one of 10 topics in the Grade 12 Physical 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. Work done by a force is calculated using which formula?
W = F.delta x.cos(theta)
W = F.delta x.sin(theta)
W = F/delta x
W = Fma
Answer: W = F.delta x.cos(theta) — Work done is W=FΔxcos(θ), where θ is the angle between the force and the displacement.
Easy
2. A force acts exactly perpendicular (90°) to an object's displacement. What work does this force do?
Zero
Maximum positive work
Maximum negative work
Cannot be determined
Answer: Zero — cos(90°)=0, so W=FΔxcos(90°)=0 — a force perpendicular to the displacement does no work.
Medium
3. A 40 N force is applied horizontally to push a crate 5 m across a floor, in the same direction as the force. Calculate the work done, in joules.
