A child whose weight is $330\,\text{N}$ begins at point X, which is at the top of a slide beside a swimming pool, as shown in Fig. 3.1. Starting from rest, the child travels to the lowest part of the slide, which is vertically $4.0\,\text{m}$ below X. The child then carries on to point Y at the end of the slide, which is vertically $1.1\,\text{m}$ above the lowest point. The child’s kinetic energy at Y is $540\,\text{J}$.
(a)[2]
Calculate how much the gravitational potential energy of the child changes between X and Y.
(b)[2]
An average frictional force of $52\,\text{N}$ acts on the child as it moves from X to Y. Using changes in energy, determine how far the child travels from X to Y.
(c(i))[2]
The child leaves the slide at point Y with a velocity directed $41^\circ$ to the horizontal. The child’s motion through the air is shown in Fig. 3.2. Point Z marks the highest point of the trajectory. Neglect air resistance. Calculate the speed of the child at point Y.
(c(ii))[2]
Calculate the speed of the child at point Z.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The change is given by $\Delta E = mg\Delta h$ or $W\Delta h$.” …