Basically I have this fucking disc and I have to find out what F is equal to in order for the disc to climb up this step/stair. Apparently, the solution is to make the normal in point B that goes the opposite way of G equal to 0, but I simply cannot understand how that helps. If I want the disc to go up the stairs, why should I get rid of the force that actually pushes and helps the ball not fall down? I am so tired just please one of you tell me why.