Force on a moving charge is given by formula
[tex]\vec F = q(\vec v \times \vec B)[/tex]
here we know that this force will be maximum when velocity is perpendicular to magnetic field
[tex]\vec F = qvB[/tex]
here we know that
[tex]v = 2.0 \times 10^5 m/s[/tex]
[tex]q = 1.6 \times 10^{-19} C[/tex]
[tex]B = 8.5 \times 10^2 T[/tex]
now we have
[tex]F = (1.6 \times 10^{-19})(2 \times 10^5)(8.5 \times 10^2) [/tex]
[tex]F = 2.72 \times 10^{-11} N[/tex]
