A child sprints up a flight of stairs four times, and the duration of each ascent is noted. For which recorded time is the child’s useful power at its maximum?
- A$10\ \text{s}$
- B$20\ \text{s}$
- C$30\ \text{s}$
- D$40\ \text{s}$
Physics 0625 · IGCSE · Energy, work and power