A 12.0 μF capacitor is connected to a power supply that keeps a constant potential difference of 26.0 V across the plates. A piece of material having a dielectric constant of 3.80 is placed between the plates, completely filling the space between them.
(a) How much energy is stored in the capacitor before the dielectric is inserted?
(b) How much energy is stored in the capacitor after the dielectric is inserted?
(c) By how much did the energy change during the insertion? Did it increase or1 decrease?
(d) Explain why inserting the dielectric (or equivalently exchanging air with the material) causes a change in the stored energy of the capacitor.

0.004056 J

0.0154128 J

Increase

Explanation:

C = Capacitance  = 12 μF

V = Potential difference = 26 V

K = Dielectric constant = 3.8

New capacitance is

Energy in the capacitor

Before insertion energy 0.004056 J

After insertion

After insertion energy 0.0154128 J

Change in energy

There is an increase in energy.

The dielectric constant of air is about 1.00059 here the dielectric constant is 3.8 which is higher so the energy increases.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.

not too sure thinking all accelerations are pointed down