OK.....the y velocity is .0135/t where t is the time it took to travel 56 cm at (4 x 103m/s) = .56/412

.0135/ (.56/412) = ( .0135 x 412) /.56 = 9.932 m/s

This velocity change from ZERO to this value occured in the time it took to cover the plate length of 26cm (.26m) at 4 x 103 m/s.

(is this written properly? 4 x 103 m/s?) 412m/s (pretty slow) .26/412 = .00063107 seconds

Acceleration in the y direction is thus the change in

velocity/time = (9.932)/.00063107 = 15738.4 m/s^2

Since F= ma Thus the force is 15738.4 ( m )

Lorentz force law : F= q(E+ v x B) = 15738.4 m divide both sides by m

q/m (E + v x B) = 15738.4

or rewritten:

q/m = 15738.4/ (E + v x B) We are given E and v which we can substitute....but we still do not have 'B' the magnetic flux density......hmmmmm .... NOW I'M STUCK! Wonder if I was given all of the information? And was the initial speed really 4 x 103 m/s ?

Think I might be on the wrong path???