A:布朗运动和扩散现象都可以在气、液、固体中发生
B:布朗运动和扩散现象都是分子的运动
C:对物体做功,同时物体吸热,物体的内能可能不变
D:物体对外做功,同时吸热,物体的内能可能不变
Our teachers have been with us for nearly three years _______ we came to junior high school. We should thank them for what they have done for us.
在某一长直的赛道上,有一辆赛车A前方x0=200m处有一辆赛车B正以vB=10m/s的速度匀速前进,这时赛车A从静止出发以2m/s2的加速度追赶.试求: