Solution to task 443 from Chertov´s for extramural stud

Solution to task 443 from Chertov´s for extramural stud

443. The alpha particle flew into the magnetic (B = 5 mT) and electric (E = 30 kV / m) fields crossed at right angles. Determine the acceleration a of an alpha particle if its velocity v (| v | = 2.106 m / s) is perpendicular to vectors B and E, and the forces acting from these fields are oppositely directed.