Bloodhound Supersonic Car
 

Is the maths here wrong or am I going mad (it could be both of course):

[URL="http://www.bbc.co.uk/news/science-environment-31845234"]Bloodhound: Superwheels for supersonic car go into production[/URL]

[QUOTE=Flatlander;397844]Is the maths here wrong or am I going mad (it could be both of course):

[URL="Bloodhound: Superwheels for supersonic car go into production http://www.bbc.co.uk/news/science-environment-31845234"]Bloodhound: Superwheels for supersonic car go into production[/URL][/QUOTE]

Corrected link:
[url]http://www.bbc.co.uk/news/science-environment-31845234[/url]

Fascinating stuff about the high-tech disc wheels - thx for the link(s).

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.

I was out by a factor of ten for some reason. :blush: