The potential at location A is 376 V. A positively charged particle is released there from rest and arrives at location B with a speed vB.

The potential at location A is 376 V. A positively charged particle is released there from rest and arrives at location B with a speed vB. The potential at location C is 784 V, and when released from rest from this spot, the particle arrives at B with twice the speed it previously had, or 2vB. Find the potential at B.