问题
问答题
（1）物体与接触面间的动摩擦因数μ＝?
（2）A、B之间的距离sAB＝?
答案
（1）0.58（2）10 m
(1) 物体在斜面上恰能匀速下滑，平行于斜面方向上的合力为零，则
mgsin30°=μmgcos30° ①
μ=
="0.58··························································" ②
(2) 设物体从A→B的运动过程中加速度大小为a1，B→C的运动过程中加速度大小为a2，则
F－μmg＝ma1··············································· ③
μmg＝ma2··················································· ④
解得a1＝
m / s2······································ ⑤
a2＝10 m / s2⑥
根据题意有
，
····· ⑦
所以
········································· ⑧
sAB＝10 m···················································· ⑨
评分标准：本题共12分，其中①③④式各2分，②⑤⑥⑦⑧⑨式各1分。