A horizontal wire is hung from the ceiling of a room by two massless strings. The wire

Question:

A horizontal wire is hung from the ceiling of a room by two massless strings. The wire has a length of 0.20 m and a mass of 0.080 kg. A uniform magnetic field of magnitude 0.070 T is directed from the ceiling to the floor. When a current of I = 42 A exists in the wire, the wire swings upward and, at equilibrium, makes an angle ϕ with respect to the vertical, as the drawing shows. Find

(a) The angle ϕ and

(b) The tension in each of the two strings.