At a certain location the earth's magnetic field is 0.00004t at an angle 40 degrees to vertical, a vertical wire carries a certain current of 15a. find the force on 20m of the wire

Adielectric-filled parallel-plate capacitor has plate area a = 30.0 cm2 , plate separation d = 9.00 mm and dielectric constant k = 3.00. the capacitor is connected to a battery that creates a constant voltage v = 15.0 v . throughout the problem, use ϵ0 = 8.85x10-12 c2/n.m2 . find the energy u1 of the dielectric-filled capacitor.