A magnetic field has a magnitude of 12 103 T and an electric

A magnetic field has a magnitude of 1.2 10-3 T, and an electric field has a magnitude of 4.3 103 N/C. Both fields point in the same direction. A positive 1.8 µC charge moves at a speed of 2.8 106 m/s in a direction that is perpendicular to both fields. Determine the magnitude of the net force that acts on the charge.

Solution

F = q E = 1.8 * 10^-6 * 4.3 * 10³ = 0.00774 N

F = q v B = 1.8 * 10^-6 * 2.8 * 10⁶ * 1.2 * 10^-3 = 0.006048 N

Magnitude Pythagorean Theorem

F = sqrt (0.00774²+ 0.006048²)

= 9.8 x 10^-3N