质量为M的物块以速度V运动,与质量为m的静止物块发生正撞,碰撞后两者的动量正好相等,两者质量之比M/m可能为[ ]
A.2
B.3
C.4
D.5
AB
— Jack, what do you think of the event which not only promoted________of the world hunger, but
raised a lot of money to help those poor children?
— That's great![ ]
A. awareness
B. contribution
C. direction
D. loneliness
A.物体的分子热运动动能的总和就是物体的内能
B.对于同一种气体,温度越高,分子平均动能越大
C.要使气体的分子平均动能增大,外界必须向气体传热
D.一定质量的气体,温度升高时,分子间的平均距离一定增大