Balrog is the resident math nut then :flip:
Can you explain how you worked out the centrifugal force thing? I bet it involves pi.
Im interested in these things 
Not a mathematician, an engineer. Can’t do complex math to save my life. Arithmetics OK though
Well its a bit wobbly this, but appproximately :-
Centripetal acceleration = w^2 r where w = rotary speed in radians/sec and r is radiuis.
Acceleration due to gravity = 9.81 m/s. To ride round the drum at an angle of 45 deg to the horizontal acceleration would have to equal the vertical acceleration.
ie 9.81 = w^2 r. or w = (9.81/r)^0.5 so after a bit of arithmetic we get w = 0.114 rad/sec. There are 2(pi) radians in 360 deg so the speed is 0.0182 rev/sec.
The circumference is 2(pi)r = 4713 metres.
So finally 4713*0.0182 = 85 metres/sec = 193 MPH
thats pretty heavy…but i think i get it. formulae are ok once you get past the initial shock ;). cheers
And i knew pi would have somthing to do with it.
I like pi :flip:
Good grief. You are totally right, and I am an idiot. I did say I was very tired, though - it was 2am, and that’s probably the average time I’ve been to sleep for the past 14 or so nights. Considering I have 9am lectures 6 days a week, and get up at 8 every morning, I’m probably down a good 28ish hours of sleep. 
Sorry about that.
Yes, .47km^3 is a lot closer.
Put it down to experience, that’s why I picked you up on it. I have to admit to doing it a lot more times than once myself. :shrug:
wouldent want to be in a helicopter over that would ya 