Physics · Grades 8–11
Work, transfer and energy accounting · Revision sheet
Track work by each force and distinguish energy from power.
Learn the idea
Work
For a constant force, work is force times displacement times the cosine of their angle.
Sign
A force in the direction of displacement does positive work; an opposing force does negative work.
Perpendicular force
A force perpendicular to displacement does zero work in this model, even when the force is nonzero.
Energy account
Transferred energy goes somewhere. Dissipated energy is not destroyed, though it may become less useful.
Explain without looking
- Why is the phrase energy is used up scientifically imprecise?
- Which angle is used in W = Fd cos θ?
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.