D Load mass m, received at point A initial velocity v0, moving in a curved tube ABC. In the AB portion of the cargo except gravity constant force Q and the resistance force R friction load on the pipe at the site AB neglected. At point B the goods without changing its speed, moves at BC portion of the pipe, where it operates the friction force of FTP except gravity, load the coefficient of friction of the tube f = 0,2 and a variable force F. Assuming the load point of the material to find the law of motion of the load the section BC. Given: m = 4,8kg; v0 = 10 m / s; Q = 12H; R = 0,2v2; ℓ = 4m; FX = -6sin (4t).