Aproton (m = 1.7 × 10−27 kg, q = +1.6 × 10−19 c) starts from rest at point a and has a speed of 40 km/s at point b. only electric forces act on it during this motion. determine the electric potential difference vb − va.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

answerscientific theory;