I'm currently in an antennas class, and while my EM is fairly strong, it's been a long time since I've done very basic electromagnetics like this question asks, so I can't clearly remember the specific details and physics properties. Any help is appreciated. 1. The problem statement, all variables and given/known data We have considered in class how an e/m disturbance is created by a positive charge that is oscillating along the z axis. Let the position of a particle with a charge of + 1 nC from the origin be described by z(t) = Asin(ωt) where ω is the angular frequency (related to the period of oscillation). a. Find expressions for the velocity and acceleration of the charge (Note: these are vector quantities) b. Find an expression for the current, I(t), associated with the motion of the charge. There are actually a few more parts, but I don't know if I need help on them just yet as such. 2. Relevant equations z(t) = Asin(ωt) I = dQ/dt (?) The charge as given in class is q+. 3. The attempt at a solution a) The first part, a), isn't too difficult, basic physics says that velocity is the time-derivative of position and likewise acceleration is the time-derivative of velocity, which leds me to: v(t) = z'(t) = ωAsin(ωt) a(t) = v'(t) = z''(t) = -ω2Acos(ωt) b) This is the part I'm stuck on. I'm not sure how to pull current out of this even though I know that current is just charge passing through a given surface per time, or I = dQ/dt. But I'm not sure how to relate it to the results of a), if it is even related to that. The best I've come up with is that IdS = vdq, but I'm not wholly sure on what to integrate nor what dS is seeing as it's a point charge on a one-dimensional line. Perhaps it's as simple as I = q*v? So would it just be I = qωAsin(ωt)?