Question

A line of positive charge is formed into a semicircle of radius R- 59.4cm, as shown in the figure below. The charge per unit length along the semicircle is described by the expression λ(θ) = λ0cos8. The total charge on the semicircle is 13.5uc. calculate the value of the constant λο. Submit Answer Tries 0/10 Calculate the magnitude of the total force on a charge of 3.15uC placed at the center of curvature. Submit Answer Tries 0/10

I don't understand why my solution did not work, I tried writing a function that gives the charge density with the variable "L", where L is the length along the circumference of the circle. Then I attempted to integrate from the lowest possible L, 0, to the highest, piR, but my answer came out as 0 (wrong). Could someone please explain to me the flaw in my method?

Answer 1

At the very first you take theta=L/R but this is wrong.Again lamda is function of theta. So it is better to integrate about theta.