Please answer everything !:(

Two point charges Q, = +4.70 nc and Q, = -1.60 nc are separated by 45.0 cm. (a) What is the electric potential at a point midway between the charges? (b) What is the potential energy of the pair of charges? What is the significance of the algebraic sign of your answer? Positive work must be done to separate the charges. O Negative work must be done to separate the charges. 2 Need Help? Read It Master It Submit Answer 4 4. [-/1 Points] DETAILS SERCP11 16.3.P.026. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER An electric field does 2.61 x 103 ev of work on an oxygen nucleus of charge 1.28 x 10 18 C. Find the change in the nucleus' electric potential and electric potential energy in joules. HINT (a) change in electric potential (in V) (b) change in electric potential energy in joules