mersenneforum.org Bloodhound Supersonic Car
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 2015-03-16, 16:38 #1 Flatlander I quite division it     "Chris" Feb 2005 England 1000000111012 Posts Bloodhound Supersonic Car Is the maths here wrong or am I going mad (it could be both of course): Bloodhound: Superwheels for supersonic car go into production Last fiddled with by Batalov on 2015-03-16 at 16:42 Reason: (link)
2015-03-16, 16:41   #2

"Kieren"
Jul 2011
In My Own Galaxy!

2·52·7·29 Posts

Quote:
 Originally Posted by Flatlander Is the maths here wrong or am I going mad (it could be both of course): Bloodhound: Superwheels for supersonic car go into production
http://www.bbc.co.uk/news/science-environment-31845234

 2015-03-16, 23:39 #3 ewmayer ∂2ω=0     Sep 2002 República de California 26·181 Posts Fascinating stuff about the high-tech disc wheels - thx for the link(s).
 2015-03-17, 07:42 #4 VBCurtis     "Curtis" Feb 2005 Riverside, CA 23·577 Posts Which maths are you doubting? radial (centripetal) acceleration = r * (angular velocity)^2. 170 rev/sec * 2pi = 1068 radians/sec. r = 45cm, so a = 510000, or 50000g after some rounding to be conservative. 10500 RPM was also claimed; divide by 60 to get the same 170 rev/sec (again, rounded for journalistic use). A number not cited in the article: 1068 rad/sec *r = 480 m/sec linear velocity of car. But a m/sec is 2.23 MPH, so 1070 MPH. That's only a little higher than the target speed record, which is averaged over a mile or more.
 2015-03-17, 18:12 #5 Flatlander I quite division it     "Chris" Feb 2005 England 40358 Posts I was out by a factor of ten for some reason.