A30 nc charge is moved from a point where v = 210 v to a point where v = -90 v . how much work is done by the force that moves the charge?

The pd between the two points is 260V .. (190 - (-70) = 260) 

1V = energy transfer of 1J/C 
Total energy transferred = 30.0^-9C x 260 J/C = 7.80^-6 J .. this is a reduction in EPE as the +charge moves from a higher (+190) to a lower potential (-70), so ∆EPE = - 7.80^-6 J 

WD = energy transferred .. .. ►WD = - 7.80^-6 J 

(Electric field direction is towards the -70V point, so the field force moves the charge)

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