Two hikers are climbing a steep set of stairs up a hill at a steady speed.
During the climb: (i) Which form of energy stored in the hikers' bodies decreases? (ii) Which form of energy of the hikers increases?
State the three physical quantities that need to be measured in order to calculate the useful power output of one of the hikers during the climb.
The two hikers climb side-by-side at the same speed all the way to the top. However, one hiker developed more useful power than the other. Suggest a reason for this difference.
533 exam-style questions on CIE IGCSE Physics 1.7 Energy, work and power, covering 1.7.1a Energy stores and energy transfers, 1.7.1b Conservation of energy, 1.7.1c Kinetic and gravitational potential energy, 1.7.2 Work done, 1.7.3 Energy resources, 1.7.3a Energy resources and electricity generation, 1.7.3b Nuclear fusion as an energy source, 1.7.3c Efficiency of energy transfer, and 1.7.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.