1. Looking to find E-field and Voltage (in pic) 2. Coulomb's Law, E=q0V, E=integralde 3. Basically i tried to split the quarter ring into halves and then integrate. It worked i got the right answer. But my professor did it in 1 step? Something about just integrating over DV? I dont get how or why since when you do E-field integration you have to account for the splitting up of dq into lamdadl, etc like i did (also in a pic). Also how did she get the same result in Number 2? I got 2 times the result because there are twice as many rings?