Consider the following. (a) Red blood cells often become charged and can be trea
ID: 250579 • Letter: C
Question
Consider the following.
(a) Red blood cells often become charged and can be treated as point charges. Healthy red blood cells are negatively charged, but unhealthy cells (due to the presence of a bacteria, for example) can become positively charged. In the figure, three red blood cells are oriented such that they are located on the corners of an equilateral triangle. The red blood cell charges are
A = 1.70 pC, B = 6.60 pC, and C = 4.30 pC.
Given these charges, what would the magnitude and direction of the electric field be at cell A?
magnitudeN/C direction
° counterclockwise from the +x axis
Explanation / Answer
E due to charge at B = 6.6*10^-12*9*10^9/(0.5*10^-3)^2 at an angle of -120 deg from x-axis
Vector form: E = -118800-j205767.635
E due to charge at C = 4.30.6*10^-12*9*10^9/(0.5*10^-3)^2 at an angle of zero deg from x-axis
Vector form: E = 154800i
total field at A = 154800i-118800-j205767.635 = 36000-j205767.635 = 208.893*10^3 N/C at an angle of -80 deg from x-axis
direction will be 280 deg in counterclock wise direction from x-axis.