57. In the area of space at the same time there are uniform and constant magnetic field with induction B = 0.2 T and perpendicular to it the electric field strength of E = 4 ∙ 105 V / m. Perpendicular to both fields moves without deviating from the straight path, the electron. What is its speed?

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)