An electron is launched into a region of constant electric field, \(\vec{E}=2 \times 10^{4} \mathrm{~N} / \mathrm{C}\) directed along the positive \(y\) axis of a rectangular coordinate system, with an initial velocity of \(2.1 \times 10^{7} \mathrm{~m} / \mathrm{s}\) in the positive \(x\) direction. How far has the electron traveled in the \(y\) direction during the time interval it takes to move \(40 \mathrm{~mm}\) in the \(x\) direction? (Even though the speed at which the electron moves is an appreciable fraction of the speed of light, ignore relativistic effects.)