[填空题]
Two railroad cars, eachwhocgb.+ ix +/a;n1w a of mass 7650 kg and traveling (ghsf)wz:td pr- (t-uy 34y fp95km/h in opposite directions, collide head-on andgy)pt( sfut4z f(drh3- :y-wp come to rest. How much thermal energy is produced in this collision? $a\times10^b$ J a = b =