I've been dropping squash balls at different temperatures from a constant height of 1m, and measuring the height they bounce up to. I understand that as you heat the squash balls, air molecules inside the ball (which has negligible increases in mass and volume) bounce again each other and the inside of the ball more often and harder, leading to more air pressure in the ball, and thus a higher bounce. Is there any equation that links pressure or temperature with a drop height and bounce height? I've been using Boyle's law, Charles law and the pressure law to find pressure, and there are existing formulae for volumes, of course, but how can I link pressure with bounce? I assume it will involve the coefficient of restitution somewhere, but I'm unsure. Thanks a lot! :)

The riser (the vertical part) of a normal household stairway is rarely more than 9 inches high. The riser of an escalator is generally around 12 inches. You'll notice this any time you have to walk up an escalator which has been turned off.

Why are the risers so much taller?

I just re-watched a show called 'megstructures' where they featured a rollercoster called kingda ka that reached over 200kph in 3.5 seconds and is also the tallest in the world. 

If we put cost aside, and only focus on a) human ability to withstand ride and b) the ability of the physical structure to withstand.  could we potentially see roller costers the height of buildings going at yet unseen speeds and heights?

i understand how some trained people can withstand g forces like fighter pilots.  But keep in mind rides need to be for general public.

Jacque and Tara Lawlor, Chelmsford, Essex, UK

(Image: alitaylor, stock.xchng)