In 8iv you have a cyclist going up the road vertically. This means that energy is transferred from chemical energy by the cyclist to allow them to gain gravitational potential energy as it is going up ‘Work done’ just refers to an energy transfer. Why might all the energy transferred be transferred to gravitational potential?. Because energy is dissipated through friction which means only some is transferred to gravitational potential.
Remember energy must be conserved, if it isn’t all being transferred to GPE then it must go somewhere else.
For question 1, the relationship just means what does the graph show. Look at the axis, as upward force in N increases so does speed in turns per minute. The next point is that it doesn’t follow a straight line (the gradient changes). This means it is non linear as it isn’t a straight line (linear)