The above shows the path of a charged particle with quantity of electricity \(+q\) and a mass of \(m\) in an \(xy\)-plane. When the particle is thrown at a \(45°\) angle to the \(+x\) direction at a speed of \(v_0\), its path is a projectile motion initially, and then shows a uniform motion after entering into the uniform magnetic field. Finally, the path becomes a projectile motion again after coming out of the the magnetic field.
What is the intensity of the magnetic field?
Gravitational acceleration is \(g\), and the amount of air resistance is negligible.