When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
By Donard de Cogan, Anne de Cogan. Donard de Cogan is at University of East Anglia, Norwich. Anne de Cogan is at City College Norwich. A good mathematical model of a physical situation leads to improved understanding.
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.