1. The problem statement, all variables and given/known data An electron is launched at a 45∘ angle and a speed of Vo = 5.0×10^6 m/s from the positive plate of the parallel-plate capacitor towards the negative plate. The electron lands 4.0 cm away. 2. Relevant equations F = ma = qE v = d/t s = vt -(1/2)at^2 x = 0.04 m 3. The attempt at a solution We can find t by using trigonometry: t = x/(cos45) yf - yi = 0 = Vo * sin(45) * t - (1/2)at^2 Vo*sin(45) = (1/2)at using F = ma = qE, a = qE/m so, Vo*sin(45) = t * qE/(2m) and using t =x/cos(45) Solving for E, E = (2m * Vo * sin(45) * cos(45))/(qx) but cos(45)*sin(45) = 1/2 Therefore, E = (Vo * m)/(q*x) At this point I plug in my constants: Vo = 5*10^6 m/s m = 9.11 * 10^-31 q = 1.6 * 10^-19 x = 0.04 However I am getting a wrong answer. Could anybody point out where it is I've gone wrong? Thanks!