A proton's speed as it passes point A is 49,000 m/s. It follows the trajectory shown in the gure below, in which the equipotential line labeled as V1 = 30 V and the equipotential line labeled as V3 = -10 V. The proton has a mass of 1.67x10'27 kg and a charge of 1.60x10'19 C. I i VI [0 v V3 What is the proton's total energy at point A? 6.83-18 q J What is the proton's speed at point B? x m