An Electron Moves with a Speed Of $8.0 \times 10 ^ { 6 } \mathrm {~m} / \mathrm { s }$

Multiple Choice

An electron moves with a speed of $8.0 \times 10 ^ { 6 } \mathrm {~m} / \mathrm { s }$ along the $+ x$ -axis. It enters a region where there is a magnetic field of $2.5 \mathrm {~T}$ , directed at an angle of $60 ^ { \circ }$ to the $+ x$ -axis and lying in the $x y$ -plane.
Calculate the magnitude of the magnetic force on the electron. $\left( e = 1.60 \times 10 ^ { - 19 } \mathrm { C } \right)$

A) $3.2 \times 10 ^ { - 12 } \mathrm {~N}$
B) $0 \mathrm {~N}$
C) $3.2 \times 10 ^ { - 10 } \mathrm {~N}$
D) $2.8 \times 10 ^ { - 12 } \mathrm {~N}$
E) $2.8 \times 10 ^ { - 10 } \mathrm {~N}$