Solving a problem in physics section 32 paragraph 40 el

40. An electron in a vacuum travels in a straight line at a constant speed υ = 5 km / s. Determine the strength H of the magnetic field created by the electron at a point at a distance r = 16 nm by electron and lying on a line passing through the instantaneous position of the electron at an angle α = 30 ° to the velocity vector of the electron.