The terminals of a 1.30 mF parallel-plate vacuum capacitor is connected to a battery that keeps a voltage of 29.6 V across the plates. Then, without disconnecting the battery, a piece of material with dielectric constant of 3.51 is inserted between the plates. After inserting the dielectric, how much energy (in Joules) is stored in the capacitor?

Energy stored in capacitor with new dielectric is 1.998 joules approximately 2 joules

Explanation:

Detailed explanation and calculation is shown in the image

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.