Q. A thin circular disk of radius R rotates with angular speed w, about an axis through the centre of the disc and perpendicular to the plane of the disc. A uniform magnetic field B acts parallel to plane of the disc. If the disc is uniformly charged with surface density, derive an expression for the magnitude of the torque on the disc.

Q. A pilot, who's mass is 80.00 kg, makes a loop-the-loop in a fast jet. Suppose that the jet maintains a constant speed of 125 m/s and that the radius of the loop-the-loop is 0.557 km. What is the apparent weight that pilot feels (i.e., the force with which the pilot presses against the seat) at the bottom of loop-the-loop?