Formula Of The Week
September 19, 2015
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PP = A * I * Cd
It is always reassuring to know that life’s little mysteries can be boiled down to a simple formula.
Take pooh sticks – not the uninviting cardboard sticks that 60 year olds receive through the post here in the UK on the advent of their 60th birthday but the game that was first mentioned in AA Milne’s The House at Pooh Corner and which has enchanted many a child. It is very simple – it needs a minimum of two players and the object of the game is to drop the sticks from the upstream side of a bridge and see whose stick appears on the other side.
The formula, devised by Dr Rhys Morgan of the Royal Society of Engineering, reveals that the perfect pooh stick (PP) is the function of the cross-sectional area of the stick – the thickness which should be as great as possible – multiplied by its density (I), which should be as great as possible, multiplied by the drag coefficient (CD) of the stick, which should be as rough as possible. It was devised, he said, after numerous games of pooh sticks.
Armed with this knowledge I am going to practise, ready for next year’s World Championship to be held at Cogges Manor Farm in Witney – a new venue after 31 years at Day’s Lock – in June next year.