- #1

PolarBee

- 14

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## Homework Statement

There is a thin rod with charge Q that has been bent into a semicircle with radius R. Find an expression for the electric potential at the center.

Radius = R

Charge = Q

## Homework Equations

V = ∫(k * dq)/r

## The Attempt at a Solution

dq = λdx

λ = Q/L

L = pi * r

V = kQ / LR ∫ dx = kQ / pi * r^2 ∫ [3pi/2 - pi/2]

V = kQ/R^2

But the answer should be kQ/R. How did the other R get cancelled?