比热容练习题想得到6kg50℃的温水,而把25℃的冷水和100℃的开水混合,问需用冷丶开水各多少?·········································································································

问题描述:

比热容练习题
想得到6kg50℃的温水,而把25℃的冷水和100℃的开水混合,问需用冷丶开水各多少?·········································································································

设用xkg冷水,(6-x)kg热水
Q末=Cm10△t=4.2X10^3X6X50=1.26X10^6J
Q冷=Cx△t=x`1.05X10^5J
Q热=C(6-x)△t=(6-x)`4.2X10^5
Q热+Q冷=Q末
x=4kg
6-x=2kg