When momentum is conserved it is called . (multiple choice) A.) Conservation of Momentum
B.) The Law of Momentum
C.) The Physics of Momentum
D.) The Rules of Momentum

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.