题型:计算题 如图所示,mA=4kg,mB=1kg,A与桌面间的动摩擦因数μ=0.2,B与地面间的距离h=0.8m,A、B原来静止,试求:(1)B落到地面时的速度为多大。(设A离桌面的右边足够长);(2)B落地后,A在桌面上能继续滑行多远才能静止下来。(g取10m/s2) 查看答案
题型:选择题 –What does your friend look like?–She is of medium build, and she has _______ hair.A.sadB.longC.busyD.small 查看答案