Part ( a ) of the figure below shows two charged particles fixed in place on an
ID: 2127663 • Letter: P
Question
Part (a) of the figure below shows two charged particles fixed in place on an x axis with separation L. The ratio q1/q2 of their charge magnitudes is 9.00. Part (b) of the figure shows thex component Enet,x of their net electric field along the x axis just to the right of particle 2. The x axis scale is set by xs = 27.0 cm.
(a) At what value of x > 0 is Enet,x maximum?
(b) If particle 2 has charge -q2 = -3e, what is the value of that maximum?
Part (a) of the figure below shows two charged particles fixed in place on an x axis with separation L. The ratio q1/q2 of their charge magnitudes is 9.00. Part (b) of the figure shows the x component Enet,x of their net electric field along the x axis just to the right of particle 2. The x axis scale is set by xs = 27.0 cm. At what value of x > 0 is Enet,x maximum? If particle 2 has charge -q2 = -3e, what is the value of that maximum?Explanation / Answer
Ex = kq2/x^2 - kq1/(L+x)^2
a) Enetx max or, dE/dx = 0
==> d/dx (kq2/x^2 - kq1/(L+x)^2) =0
==> -kq2/x + kq1/(L+x) = 0
==> kq2/x = kq1/(L+x)
==>L+x/x = q1/q2 = 9
==> L/x +1 = 9
==> L/x = 8
==> x = L/8
b) Ebet,max = kq2/(L/8)^2 - kq1/(L+L/8)^2
== 64*k*3e/L^2 - 64*k*27e/81L^2
== 64*k*3e/L^2 (1 -9/81)
==64*k*3e/L^2 (1-1/9) = (64*k*3e/L^2)*(8/9)
==> Enet,max = 512*k*3e/3L^2