A child on a sled starts from rest at the top of a hill (point P). The sled slides down the slope, increasing in speed, until it reaches a flat gravel path at the bottom (point Q), where friction causes it to grind to a complete stop.
Which of the following sequences correctly describes the energy changes that have taken place between point P and point Q?
gravitational potential energy →\rightarrow→ kinetic energy →\rightarrow→ thermal energy
gravitational potential energy →\rightarrow→ thermal energy →\rightarrow→ kinetic energy
kinetic energy →\rightarrow→ gravitational potential energy →\rightarrow→ thermal energy
kinetic energy →\rightarrow→ thermal energy →\rightarrow→ gravitational potential energy
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.