[Mentor's note: no template because this thread was moved into the homework forum after it had already attracted several useful replies] [Mentor's note: Thread title changed to reflect question content] The question is: An electron is a subatomic particle (m = 9.11 10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +5.71 105 m/s to a final velocity of +2.03 106 m/s while traveling a distance of 0.037 m. The electron's acceleration is due to two electric forces parallel to the x axis: vector F 1 = +8.08 10-17 N, and vector F 2, which points in the -x direction. Find the magnitudes of the net force acting on the electron and the electric force vector F 2. Vf= final velocity Vi = initial velocity Fn= net force d= distance F1= forces parallel to x-axis to get acceleration I did: (Vf)^2- (Vi)^2 / 2d and I got 5.128 m/s^2 I then calculated Fn= ma = 4.671 N To get F2 I did F1- Fn and got -4.671N but Webassign told me these are wrong, and I've already done other things and got other (wrong) answers... what am I doing wrong? This seems fairly straightforward. Thanks!