Proton in a well . Figure 24-51 shows electricpotential V along an x axis.A prot

Question

Proton in a well. Figure 24-51 shows electricpotential V along an x axis.A proton is to be released at x = 3.6 cm withinitial kinetic energy 3.0 eV. The scale of the vertical axis isset by Vs = 10.0V. (a) If it is initially moving in thenegative direction of the axis, it either reaches a turning point(if so, what is the x coordinate of that point)or it escapes from the plotted region (if so, what is its speedat x = 0)? (b) If itis initially moving in the positive direction of the axis, iteither reaches a turning point (if so, what isthe x coordinate of that point) or it escapesfrom the plotted region (if so, what is its speedat x = 6.0cm)? (c) What is the electric force(including sign) on the proton if the proton moves just to the leftof x = 3.0cm? (d) What is the electric force(including sign) on the proton if the proton moves just to theright of x = 5.0 cm?

Explanation / Answer

If it move to the right, i ill escape from the well. Ki+Wi=Kf+Wf so Kf=K1+Wi-Wf=3+3-5=1eV=mv^2/2 so v=sqrt(2Kf/m)=5,93e5(m/s) If it move to the left, the proton will turn back. At that point Kf=0 so Wf=K1+Wi=6eV so x=2cm c)If the proton move a bit to the left, its velocity decrease. So the force act on the proton head toward the positive x axis. E=V/x=6V/2cm=300(V/m) so F=Eq=4,8e-17(N) d)If the proton move a bit to the right at the point x=5cm its velocity is also decrease so the force now head toward thenegative x axis. E=V/x=2V/1cm=200(V/m) so F=Eq=3,2e-17(N)

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.