A proton moving with a speed of 200 m/s enters perpendicular to the direction of the magnetic field and experiences a force of 2 * 10 ^ -18 N. What is the magnitude of the magnetic field?

0.0625 T

Explanation:

When a charged particle is moving in a region with a magnetic field, the particle experiences a force given by the equation

where

q is the charge of the particle

v is its velocity

B is the magnitude of the magnetic field

is the angle between the direction of the velocity and of the field

For the proton in this problem, we have:

is the force experienced

is the charge of the proton

is its velocity

, since the proton enters the region perpendicular to the magnetic field

Therefore, we can re-arrange the equation to find B:

if they have a finite resultant