A particle of charge \( q \) and mass \( m \) is projected from origin with an initial velocity \( \vec{v}=\left(\dfrac{v_0}{\sqrt{2}}\hat{x}+\dfrac{v_0}{\sqrt{2}}\hat{y}\right) \).
There exists a uniform magnetic field \( \vec{B}=B_0\hat{z} \) and a space varying electric field \( \vec{E}=E_0 e^{-\lambda x}\,\hat{x} \) within the region \( 0\le x\le L \). After travelling a distance such that x-coordinate has changed from \( x=0 \) to \( x=L \), the change in the kinetic energy is ____________ .