Skinny v wide - I sense many Threaders are still sceptical re my postulation wide wheels grip no better than skinny - no problem, scepticism is an essential milestone on our journey to the truth, but to round matters up I thought I would record, as accurately as I can, the actual lab experiment on my Erdington Tech Engineering Course all those years ago (1965-66) it's gonna take me a bit of time to search the dark crevices of my mind but in the mean time I'm delighted to report Mrs M's interest in the project remains as strong as ever.......
As promised attached is the set-up for the actual experiment I undertook some 53 years ago. Seems straight forward,
right? Not quite - there are in fact
2 values for the coefficient of friction of materials: static and kinetic. the static value is higher because the effort to get a load from rest to moving is higher than that needed to keep the load moving, all my references relate to kinetic.
The result was 0.2 for wood on wood, in simple terms the effort needed to drag the wood was 20% of the weight. Rubber gives a much higher value and can approach 0.9, car tyres are around 0.7+.
So does any of this affect our everyday lives? Well, I wonder if Scott of the Antarctic carried out such a calculation to detemine the maximum load his ponies could pull on their sledges?
I know what youi are thinking:
But Scott didn't make it.True,
not the best example, perhaps. Peg.