(i)[2]
Show that $k=6.25$.
(ii)[4]
Find the greatest steady speed of the runner while moving uphill on a straight path inclined at an angle $\alpha$ to the horizontal, where $\sin\alpha = 0.05$.
Mathematics 9709 · AS & A Level · Forces and equilibrium
Forces and equilibrium — practice question
The force resisting a runner of mass $70\,\text{kg}$ is $kv\,\text{N}$, where $v\,\text{m s}^{-1}$ represents the runner’s speed and $k$ is a constant. The maximum power the runner can produce is $100\,\text{W}$. The runner’s highest steady speed on horizontal ground is $4\,\text{m s}^{-1}$.
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