🚀 go-pugleaf

Frank E Perdicaro writes:
: As an interesting side light, the largest forging ever made is 
: the largest flywheel ever that stores energy at MIT for the 
: ALCATORC-MOD fusion reactor.  It takes like 500 hp all night to spin it up, 
: and 3 seconds to stop when the switch is flipped.  
: 
: Yeah, megajoules, many of them.  If there was a quake when the thing
: was spinning, it would remove a large section of Cambridge.  
: 
: Its surface speed is just below the speed of sound, and it weighs like
: a very large steam locomotive ; and its right next to the FISSION
: reactor..... they know there is no way to stop it if there is a quake,
: so its just in a simple flimsy building.

I have a problem with this; if v^2 ~= 1e5 (m/s)^2 and you've pumped in
about 3MJ, the mass must be about 60Kg for a disc shape. Perhaps the speed
is not nearly so high - this is hardly a locomotive weight!
(Hint: use Disc Energy = 0.5m(r*w)^2 and 1hp = 764W).

Andrew Palfreyman