If you remove possible gaming capabilities, well, about any laptop from $300 to $700 depending on your brand preferences will do just as fine. Paid my Core2Duo from Acer a year or two ago like $500 and it browses web, display HD like a boss, I have no idea what/how those physics/math programs work so no idea there...
If you add gaming capabilities to the equation AND restrict it to $900, this is pretty much the only laptop I could find on newegg that corresponds
http://www.newegg.com/Product/Produc...82E16834114803
It /should/ (and I really mean /should/) do game fine long as you're not planning maxed settings on high resolution.