AQA Paper 1 2019 June — Question 15

Exam BoardAQA
ModulePaper 1 (Paper 1)
Year2019
SessionJune
TopicParametric equations

15
  1. At time \(t\) hours after a high tide, the height, \(h\) metres, of the tide and the velocity, \(v\) knots, of the tidal flow can be modelled using the parametric equations $$\begin{aligned} & v = 4 - \left( \frac { 2 t } { 3 } - 2 \right) ^ { 2 }
    & h = 3 - 2 \sqrt [ 3 ] { t - 3 } \end{aligned}$$ High tides and low tides occur alternately when the velocity of the tidal flow is zero.
    A high tide occurs at 2 am.
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    1. Use the model to find the height of this high tide.
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  2. (ii) Find the time of the first low tide after 2 am.
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  3. (iii) Find the height of this low tide.
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  4. Use the model to find the height of the tide when it is flowing with maximum velocity.
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  5. Comment on the validity of the model.