## Gina 5 years ago help me please!!,,,to the plate plane air capacitor applied potential difference U = 500V in the area of ​​the plates with a = 200 cm square, the distance between d1 = 1,5 mm. plates moved apart to a distance d2 = 15mm. find the energy E1 and E2 of the capacitor before and after razdvizheniya plates, if the source of EMF to razdvizheniem: 1) switched off, and 2) does not turn off. (1) E1 = 14,8 mJ, E2 = 148mkdzh; 2) E1 = 14,8 mJ: E2 = 1,48 mJ

can you explain what is "razdvizheniem"

2. Gina

that is supposed to the word( motion),,,i translated from russian to english

you have given answer also ... you need procedure ... right ?

4. Gina

yes,plesae

answers are in milli J or in micro J .... coz ... I am getting answers in micro J

6. Gina

$\int\limits_{o}^{a}d _{x}$

7. Gina

what is important is the procedure os can you show me ?

I am typing ... I will send in few minutes ..

9. Gina

o right

Formulas required $C=\epsilon_0\frac{A}{d}$ $Q=CV$ $E=\frac{1}{2}CV^2$ given $A=200 cm^2 = 0.02 m^2$ $d_1=1.5 mm= 1.5e-3 m$ $d_2=15 mm= 15e-3 m$ Calculating Capacitance: $C_1=1.1805e-010$ $C_2=1.1805e-011$ Case 1: when external supply voltage is cut off before movement voltage is give as $V_1=500$ Finding charge $Q=C_1V_1=5.9027e-008$ after movement charge is constant. So voltage changes to $V_2=\frac{Q}{C_2}=5000$ Finding energy $E_1=\frac{1}{2}C_1V_1^2=1.4757e-005 \approx 14.8\mu J$ $E_2=\frac{1}{2}C_1V_1^2=1.4757e-004 \approx 148 \mu J$ Case 2: when external supply voltage is maintained at 500V Voltage is constant V_1=V_2=V=500v Finding energy: $E_1=\frac{1}{2}C_1V^2=1.4757e-005 \approx 14.8\mu J$ $E_2=\frac{1}{2}C_1V^2=1.4757e-006 \approx 1.48\mu J$

Gina .... I did a mistake .... in the formula of E2 .... the capacitance is not C1 ... it is C2

12. Gina

wow!! thank you very much))

welcome

14. Gina

ok i will check on it

15. Gina

mr.sgadi do have the notes on this topic?

I don't have any special notes regarding this topic. I used Wikipedea. http://en.wikipedia.org/wiki/Capacitance

17. Gina

thanx again)

:-) welcome

19. Gina

I didn't understand. Can you elaborate?

21. Gina

$\int\limits_{0}^{a?}d _{x}$

22. Gina

can help mathamatics?

yes... to an extent. place in new thread so that everyone will be able to help you.

24. Gina

can help mathamatics?

26. Gina

$d _{x}\div \sqrt{x ^{2}+x+1}$

$\int{\frac{1}{\sqrt{x^2+x+1}}dx}=\ln{(x+\sqrt{x^2+x+1}+0.5)}$

28. Gina

yes that is the question

29. Gina

is that the solution?