A level 高中力学运动学计算.

A level 高中力学运动学计算.
这是Alevel数学.（带翻译）
A particle of mass 0.1kg is at rest at a point A on a rough plane inclined at 15 degrees to the horizontal.The particle is given an initial velocity of 6m/s and starts to move up a line of greatest slope of the plane.the particle comes to instantaneous rest after 1.5s.
1.find the coneffiecient of friction between the paricle and the plane.
2.shou that,after coming to instantaneous rest,the particle moves down the plane.
3.find the speed with which the particle passes through A during its downward motion.
中文大体翻译
一0.1千克的质点在一个粗糙的15度的斜面上的A点保持平衡.给予这个质点向上的初速度6m/s,质点开始移动直到斜面最高点.1.5秒后质点到达一个停顿瞬间（应该就是v等于0）
算出摩擦系数
说明,在停顿之后,质点向下移动
算出在质点下降到A时的速度