1. Write an equation for the sum of the forces acting on the car parallel to the plane and also for the sum of the forces acting on the descending mass. Note the car and descending mass both move with constant velocities.
2. If the mass of the connecting string is small compared to the other masses, F and T will be approximately equal. Use this result to combine the equations and solve for the force of friction "f" in terms of the masses and angle.
