A positron moving from a Charged Plate to Another [SOLVED] Can you solve the question a and b and explain it to me ? What i know ? ( I'm not sure though ); Kinetic Work = Kinetic Energy = 1/2 m . v^2 Electrical Work = Electrical Energy = q.V So at the begin, the positron isn't moving, so it has Potantial energy maybe... At the point K its Energy; 3V.q.(1/3d).d = V.q (?) At the point L its Energy; Vq - 4V.q.(1/2d).d = -Vq (?) ( How can energy be negative ? Oops ? ) a)EnergyK/EnergyL = ? b) speedK / speedL = ?