Answer:
[tex]\Delta U = 0.2072 J[/tex]
Explanation:
Potential difference between two points in constant electric field is given by the formula
[tex]\Delta V = E.\Delta x[/tex]
here we know that
[tex]E = 370 N/C[/tex]
also we know that
[tex]\Delta x = 2.1 - 1.9 = 0.2 m[/tex]
now we have
[tex]\Delta V = 370 (0.2) = 74 V[/tex]
now change in potential energy is given as
[tex]\Delta U = Q\Delta V[/tex]
[tex]\Delta U = (2.80 \times 10^{-3})(74)[/tex]
[tex]\Delta U = 0.2072 J[/tex]