4. A charged particle with a mass of 0.5 grams is moving at a constant speed of 750 m/s in a circular path with a radius of 12 m in a region of space where there is a 1.2 T magnetic field perpendicular to the plane of the circle. What is the charge of the particle? (Solve problems with magnetic force and Newton's 2nd law including centripetal acceleration and know). 5. A 1.5 m horizontal wire with a current of 15 A north is suspended in air by a 2.0 T magnetic field pointing west. What is the mass of the wire? (Solve problems with the magnetic force on a wire with a current and use that force in problems involving Newton's 2nd law). ded in air because another wire is placed