A particle with charge $7\mathrm{.}80$ mC is moving with veloc$-$

ity v

S

$=(3\mathrm{.}80*10^3$

m$>$s$^2).$ The magnetic force on the particle

is measured to be F

S

$=+(7\mathrm{.}60*10^3$

N$)$i $(5\mathrm{.}20*10^3)$k

$.$

$($a$)$ Calculate all the components of the magnetic field you can

from this information. $($b$)$ Are there components of the magnetic

field that are not determined by the measurement of the force?

Explain. $($c$)$ Calculate the scalar product B

S

~ F

S

$.$ What is the angle

between B

S

and F

S

$?$