Halliday, Resnick & Walker — Electric Potential: Problem 40

40 Proton in a well. Figure 24-41 shows electric potential \(V\) along an \(x\) axis. The scale of the vertical axis is set by \(V_s = 10.0 \text{ V}\). A proton is to be released at \(x = 3.5 \text{ cm}\) with initial kinetic energy \(5.00 \text{ eV}\). (a) If it is initially moving in the negative direction of the axis, does it reach a turning point (if so, what is the \(x\) coordinate of that point) or does it escape from the plotted region (if so, what is its speed at \(x = 0\))? (b) If it is initially moving in the positive direction of the axis, does it reach a turning point (if so, what is the \(x\) coordinate of that point) or does it escape from the plotted region (if so, what is its speed at \(x = 6.0 \text{ cm}\))? What are the (c) magnitude \(F\) and (d) direction (positive or negative direction of the \(x\) axis) of the electric force on the proton if the proton moves just to the left of \(x = 3.0 \text{ cm}\)? What are (e) \(F\) and (f) the direction if the proton moves just to the right of \(x = 5.0 \text{ cm}\)?