5 ms·
That's my point. The wiki definition you have cited is correct, but it doesn't compute with the article.
by GalacticDomin8r 9y ago
That's my point. The wiki definition you have cited is correct, but it doesn't compute with the article.
- DannyBee 9y agoI'll save everyone else the trouble. The original data is from https://www.aaafoundation.org/sites/default/files/2011PedestrianRiskVsSpeed.pdf https://www.aaafoundation.org/sites/default/files/2011Pedest... If you look, on page 9, you can see the plots of impact speed vs risk of death. They are clearly non-linear, and they you can also read that they tried various fitting methods for missing data (and quadratic best fit things). I'm just guessing that you are confused because it does not appear the constant for the x^2 term is >1.
- GalacticDomin8r 9y agoI'll make it even easier: http://hyperphysics.phy-astr.gsu.edu/hbase/impcal.html#c1 http://hyperphysics.phy-astr.gsu.edu/hbase/impcal.html#c1
- scotty79 9y agoQuadratic relationship is between the speed and force of impact. If you want to accelerate pedestrian to certain speed you have to pump kinetic energy into him. You do that by applying a force over some distance (distance is how much pedestrian will squish during impact before it starts moving with the car) so to acellerate to double speed, you need to pump in quadruple energy, you need to quadruple the force since squishing distance is the same (until you reach speeds that pulverize pedestrian bones).
- scotty79 9y agof(x)=a*x^2 f(2*x)=a*(2*x)^2=a*4*x^2=4*a*x^2=4*f(x) Doubling the argument quadruples the value of quadratic function.
- GalacticDomin8r 9y agoTry again using order of operations. It does not expand to (2*x)^2, it is simply 2x^2. To say it another way: 4x^2 != 2x^2