XBOX 360 PROBLEM HELP ASAP PLEASEESSSS!!!!!!!!?

well here the thing i was playing MW2 when my brother bumped into my XBOX 360 now it wont read mw2 but it will read all my other games.I have also tried a new MW I borrowed from a friend will not read it either. WONT even read any modern warfare or CoD games but will read all my other games. when i put MW2 or CoD into the tray and close it, i says reading then it says open tray??? WTH please help me!!!!!!!!!!!!!!!!!!!!!!! Its my cousins XBOX 360