2 A proton moves with a velocity of $\vect{v} = (2\ihat -4\jhat
3 +\khat)\U{m/s}$ in a region in which the magnetic field is $\vect{B} =
4 (\ihat + 2\jhat -3\khat)\U{T}$. What is the magnitude of the magnetic
5 force this charge experiences?
6 \end{problem*} % problem 22.6
10 \vect{F} &= q \vect{v}\times\vect{B}
13 \ihat & \jhat & \khat \\
18 = q [\ihat(12-2) -\jhat(-6-1) +\khat(4-(-4))]
19 = q (10\ihat+7\jhat+8\khat) \\
20 |\vect{F}| &= q \sqrt{10^2+7^2+8^2}
21 = \ans{2.34\E{-18}\U{N}}