A charged particle (m = 5.0 g, q = −70 μC) moves horizontally at a constant speed of 30 km/s in a region where the free fall gravitational acceleration is 9.8 m/s² downward, the electric field is 700 N/C upward, and the magnetic field is perpendicular to the velocity of the particle. What is the magnitude of the magnetic field in this region? A) 47 mT B) zero C) 23 mT D) 35 mT E) 12 mT

Question

Quizplus · Accepted Answer

The gravitational force is balanced by the electric force and the magnetic force. The magnetic force is zero because the velocity is constant, so the electric force equals the gravitational force. Solving for the magnetic field gives 47 mT.

A Charged Particle (M = 5