1. The problem statement, all variables and given/known data So for a project, we decided to do tension strings that would be attached to a wheelchair inside a subway so that when the subway decelerates or accelerates, the wheelchair wouldn't move. However, due to our inexperience we used only the wheel and solved for equations. If I'm not mistaken when the subway is deccelerating, the force (ma) is applied to the left, the friction force would also be to the left (since it's movement would keep going right due to inertia) and the Tension would go to the right, even if the tension cables are attached to the left. Something like it was attached So what we wanted to find was what was the Tension force necessary so that the wheel wouldnt move. uk = 0.20 radius = 0.3048m mass = 89.67 acceleration = +- 1.5m/s^2 Since I can't seem to attach any file Tension -> Normal would be going up ^ mg would be going down v and Force + friction force would be going to the left <- 2. Relevant equations Sum of forces in x: T - F - f = 0 Sum of forces in y:N - mg = 0 Torque force = r x F Sum of torques?? 3. The attempt at a solution Normal force = 878.766 Friction force = 175.752 Applied force = 134.505 Torque force = 0.3048 * 175.752 * sin 90 = 53.5692 The problem is that I am not sure at all on how to use the torque force or if im supposed to use this in a sum of torques equation etc.