SAT2 牛顿定律一题 急阿急!
p75,第10题,谢咯!
图是一个定滑轮,有一个人在拉一端,滑轮上升.
题：A force of 20N horizontally on a mass of 10 kg being pushed up a frictionless incline that makes a 30度 angle with the horizontal as shown below.(图上啥也没.)The magnitude of the acceleration of the mass up the incline is equal to
17m/s2
还是不懂啊＝ 人对绳子的拉力要算么？合力方向是30度的方向么？