WAB=qUAB
UAB=WAB/q=1.5*10的-7/2.0*10的-9次方=75v
WAC=qUAC
UAC=WAC/q=-4.0*10的-7J/2.0*10的-9次方=-200v
UAB+UBC=UAC
所以UBC=UAC-UAB=-200-75=-275V
WAB=qUAB
UAB=WAB/q=1.5*10的-7/2.0*10的-9次方=75v
WAC=qUAC
UAC=WAC/q=-4.0*10的-7J/2.0*10的-9次方=-200v
UAB+UBC=UAC
所以UBC=UAC-UAB=-200-75=-275V