negative point charge 10-8 coulomb is situated in air at the origin of a rectangular coordinate system. What is the electric field intensity at a point on the positive x direction 3 metres from the origin?
Let's provide some denominations: q = - 10^(-8) coulomb - the charge of the point r = 3m - distance from the point
The intensity of the electric field is
E = k*q/r² = 8.9877*(-10^(-8))/3² = 8.9877*10^(-8)/9 = 0.99863*10^(-8) N/coulomb.