What are the components of Inner Parts of the Solar Nebula Disk? What are the components of Outer Parts of the Solar Nebula Disk?

Find an expression for the electric field e⃗ at the center of the semicircle. hint: a small piece of arc length δs spans a small angle δθ=δs /r, where r is the radius. express your answer in terms of the variables q, l, unit vectors i^, j^, and appropriate constants.