Formula for an unbeatable poohstick

Winnie the Pooh. Picture: Supplied

Winnie the Pooh. Picture: Supplied

Published Aug 26, 2015

Share

London - For a Bear of Very Little Brain it may be a little too complicated.

But if Winnie the Pooh were able to get his head round a leading engineer’s work he would find an apparently surefire way of winning at his beloved poohsticks.

Dr Rhys Morgan claims to have found the formula for a perfect stick – which he says should be as thick, dense and rough as possible.

These properties, Dr Morgan adds, increase the drag, which means the water will have greater influence on the stick, thus carrying it away more quickly.

It will also sink sufficiently below the surface, where the fastest part of the stream lies, he claims.

The game of poohsticks first appeared in A. A. Milne’s classic children’s story The House at Pooh Corner in 1928. It involves participants dropping sticks over one side of a bridge and walking over to the other side to see which one appears first.

It was voted one of Britain’s most popular traditional games in a poll of 2 000 parents, with a quarter naming it as their favourite behind hide and seek and “It’”

Almost 60 percent of poohstick players regard it as a simple game of chance, according to the research conducted to mark the release of The Poohsticks Handbook: A Poohstickopedia by Mark Evans.

But Dr Morgan, of the Royal Academy of Engineering, suggests that a little research into a stick’s properties could go a long way to securing you an advantage.

He has spent countless hours playing the game and has now devised a formula he says will give children – and parents – the competitive edge.

He said the main variables to be considered are the stick’s cross-sectional area (A), which affects the amount of stick in contact with the water, its density/buoyancy (?), and the drag coefficient Cd, giving us the formula for a Perfect Poohstick: PP = A x ? x Cd.

Dr Morgan suggests that a larger cross-sectional area is good as this increases the amount of the stick’s surface in contact with the water.

Normally, a large cross-sectional area decreases speed but with poohsticks, drag is key. If more water is able to influence the trajectory of the stick, it will accelerate more quickly. So the tubbier the stick, the better. Similarly, a higher density is better. The density of the stick affects its position in the water. The fastest part of the stream is below the surface, so the a stick that sinks slightly will go faster than a stick which is floating right on the surface.

The drag coefficient is determined by the shape of stick and roughness of its surface. Generally, a rough stick will create more drag than a smooth stick, so in general, bark is good. However according to Dr Morgan, a certain roughness can make the stick ‘apparently’ smoother, similar to the effect created by dimples in golf balls, so choose carefully.

To complement Dr Morgan’s research, VisitEngland has come up with the best 12 poohstick bridges in the UK, in addition to the original Poohsticks Bridge in Ashdown Forest, East Sussex:

The top three are Sheepwash Bridge, in Ashford-in-the-Water, Derbyshire; Morden Hall Park, in London; and Heale Gardens, in Salisbury, Wiltshire.

Daily Mail

Related Topics: