(a)[4]
Calculate the child’s speed at $Y$.
(b)[6]
It is stated that the child comes to rest at $Z$. Use an energy method to determine the coefficient of friction between the child and $YZ$, and give your answer as a fraction in its simplest form.
Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
The diagram presents the vertical cross-section $XYZ$ of a rough slide. $YZ$ is a straight segment of length $2\,\text{m}$ that makes an angle of $\alpha$ with the horizontal, where $\sin\alpha = 0.28$. At $Y$, $YZ$ touches the curved part $XY$ tangentially, and $X$ is $1.8\,\text{m}$ above level of $Y$. A child of mass $25\,\text{kg}$ slides down the slide, beginning from rest at $X$. The work done by the child against the resistance force in moving from $X$ to $Y$ is $50\,\text{J}$.