A parallel-plate capacitor has a capacitance of 10 mF and charged ...

[student77]

A parallel-plate capacitor has a capacitance of 10 mF and charged with a 20 V power supply. The power supply is then removed and a dielectric of dielectric constant 4 is used to fill the space between the plates.
 
  The energy now stored by the capacitor is A)
 
  250 mJ.
  B)
 
  125 mJ.
  C)
 
  500 mJ.
  D)
 
  zero.
  E)
 
  62.5 mJ.

Question 2

The angular velocity of a wheel is given by (t) = (2.00 rad/s2)t + (1.00 rad/s4)t3.
 
  (a) What is the angular displacement of the wheel from time t = 0.00 s to time t = T?
  (b) What is the angular acceleration of the wheel as a function of time?

[akemokai]

Answer to Question 1

C

Answer to Question 2

(a) (1.00 rad/s2 )T2 + (0.250 rad/s4 )T4
(b) (2.00 rad/s2 ) + (3.00 rad/s4 )t2

[student77]

Gracias!

[matt95]

Great answer, keep it coming