Solution to task 442 from Chertov´s for extramural stud

Solution to task 442 from Chertov´s for extramural stud

442. The ion, having passed the accelerating potential difference U = 645 V, flew into homogeneous magnetic (B = 1.5 mT) and electric (E = 200 V / m) fields crossed at right angles. Determine the ratio of the charge of an ion to its mass if the ion moves in a straight line in these fields.