72. (a) Equating the magnitude of the electric force (Fe= eE) with that of the magnetic force (Eq. 28-3), we obtain B = E /vsin φ. The field is smallest when the sin factor is at its largest value; that is, when = 90°. Now, we use Kmv=122to find the speed: vKme==×××=×−−22 2 5 10160 10911 10296 10319317...eVJ eVkgmschchThus, BEv××−10 1034 10374VmT... The direction of the magnetic field must be perpendicular to both the electric field (
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This note was uploaded on 06/03/2011 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.