124. Solving a chemistry problem

In experiments on electrophoresis, the average distance over which charged particles are displaced over a certain time under the influence of an electric field and as a result of Brownian motion, x=hel±xsv (xsv-root-mean-square displacement as a result of Brownian motion), is observed. Suppose, for spherical particles with a radius of 5 nm, an electrophoretic mobility of 4.00 * 10-7 m2 / (V * s) is measured in water at 20 C (viscosity 1.00 mPa * s). Calculate the maximum (xmax=hel-hsq) and minimum (xmin=hel-hsq) displacement of individual particles in 20 seconds in an electric field of 400 V/m.