Two students, Alice and Bob, try to move identical school bags, A A\,A and BBB, which are initially on the floor. Alice exerts a horizontal force to push bag A A\,A along the floor, but the bag does not move because it is trapped under a heavy desk. Bob lifts bag B B\,B vertically from the floor onto a desk.
Which student does work on their bag, and which bag gains the most gravitational potential energy?
Student doing work: Alice; Bag gaining most energy: AAA
Student doing work: Alice; Bag gaining most energy: BBB
Student doing work: Bob; Bag gaining most energy: AAA
Student doing work: Bob; Bag gaining most energy: BBB
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.