The difference in rate is simply to do with the physics of heat capacity and heat flow. (realclimate.org)
The reason why head on collisions are more dangers has to do with the physics behind them. (newmexicoinjury.com)
For more information on possible career options, check out our article on what you can do with a physics degree on our graduate careers website TARGETjobs. (targetcareers.co.uk)