In an experiment, a current of 3.5 A is being passed through a copper sulfate solution in a 10 cm cubical container, with the electrical terminals being opposite faces. This contains equal numbers of Cus and SO4- ions which have respectively +2 and -2 electron charge units. Assuming that the two ions have equal speed in the solution, and that there are 6.0 x 102 of each per cubic metre of the solution, work out their mean speed to 2 significant figures