(a)[3]
Describe the energy-store transfers that take place while the load is being lifted.
(b(i))[1]
Use the input energy and the useful output energy to show why the efficiency is less than $100\%$.
(b(ii))[2]
Explain how the conservation principle of energy is used when the load is lifted.
(c)[2]
A motor has an input power of $15\,\text{W}$. It runs for $20\,\text{s}$. Its efficiency is $60\%$. Calculate the energy supplied to the load.