An electric winch on a construction site is used to lift a package of building materials. The electric motor that drives the winch is powered by rechargeable batteries.
State the form of the energy stored in the batteries.
The winch raises a package of mass 45 kg through a vertical distance of 6.0 m in 8.0 s. Take the acceleration of free fall g=10 m/s2g = 10\text{ m/s}^2g=10 m/s2.
Calculate the gravitational potential energy gained by the package.
The efficiency of the winch mechanism is 0.75 (75%). Calculate the input power to the winch mechanism.
The batteries are recharged from a mains voltage supply that is generated in a coal-fired power station. By comparison with a solar farm, state one advantage and one disadvantage of running a power station using coal.
advantage:
disadvantage:
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.