On 26/05/2017 11:35, Nick wrote:
On 26/05/2017 10:34, Tim Streater wrote:

He ought to be getting that from his Physics classes - friction,
rolling balls down inclined planes, etc.


It was a while ago. I'll ask him but I suspect seeing an experiment
demonstrated once is the same as having personally tried it and got it
wrong many times. For instance the tent peg question.

Another question with no unconditionally correct answer. It would depend
partly on the ground conditions, as anyone who has done a lot of tenting
would know full well.

bill