A firefighter climbs a ladder during a training exercise to reach a platform.
The training officer measures the vertical height of the platform. What measuring instrument should they use?
The height of the platform is 4.5 m. The total mass of the firefighter and their gear is 80 kg. gravitational field strength=9.8 N/kg\text{gravitational field strength} = 9.8\text{ N/kg}gravitational field strength=9.8 N/kg
Calculate the increase in gravitational potential energy of the firefighter. Use the equation:
gravitational potential energy=mass×gravitational field strength×height \text{gravitational potential energy} = \text{mass} \times \text{gravitational field strength} \times \text{height} gravitational potential energy=mass×gravitational field strength×heightDuring the climb, the firefighter did 3500 J of work. The time it took to climb the ladder was 5.60 s.
Calculate the power of the firefighter. Use the equation:
power=work donetime \text{power} = \frac{\text{work done}}{\text{time}} power=timework doneAt the top of the ladder, the firefighter runs onto the platform with a speed of 2.5 m/s.
Calculate the kinetic energy of the firefighter. Use the equation:
kinetic energy=0.5×mass×(speed)2 \text{kinetic energy} = 0.5 \times \text{mass} \times (\text{speed})^2 kinetic energy=0.5×mass×(speed)244 exam-style questions on AQA GCSE Physics 1.1 Energy changes in a system, and the ways energy is stored before and after such changes, covering 1.1.1 Energy stores and systems, 1.1.2 Changes in energy, 1.1.3 Energy changes in systems, and 1.1.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.