So I have two questions relating to potential difference 1.An electron with a velocity of 5.0x10^6 m/s injected into a parallel plate apparatus through a hole in the positive plate. it moves across the vacuum between the plates, colliding with negative plate at 1.0x10^6 m/s. what is the potential difference between the plates? (mass of electron = 9.1x10^-31 kg) 2.Two alpha particles (mass 6.6x 10^.27 kg. charge = 3.2 x 10^ -19c) separated by an enormous distance, apporach each other along a "head on collision" path. Each has a speed of 3.0x10^-19m/s to begin with. Calculate their minimum separation, assuming no deflection from their original path. I tried with 0.5mv^2 = Eqd for the first question, but there is no charge or distance given. I saw another way where is 0.5mv^2 = qV but still there is no charge given to solve. For the second question I am kind of clueless.. Somebody help ..