Sphere suspended against a wall (PhysCasts)

The following PhysCast is about a sphere which is attached to a wall. A uniform sphere of mass m = 0.85 kg and radius r = 4.2 cm is held in place by a massless rope attached to a frictionless wall a distance of L = 8.0 cm above the centre of the sphere. Find (a) the tension in the rope and (b) the force on the sphere from the wall