Astudent measure the mass of an 8 cm^3 block of brown sugar to be 12.9 g. what is the density of the brown sugar?

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.