Question

a resistor (of unknown constant resistance) and a 0.02 farad capacitor are connected to a series with an emf of E = 100 volts. the initial charge of the capacitor is 5 coulombs. if at t=1/10 second the current flowing is 30/e amperes on the reverse direction, find the value of the resistance

answer: 5 ohms

Answer 1

this is math portion

Answer 2

?

Answer 3

go to the physics portion

Answer 4

hmm you do know this is calculus right @hba

Answer 5

soo still its a physics question

Answer 6

nope. it's DIFFERENTIAL EQUATIONS. physics people cant help in this kind of problem. i'll be posting in the wrong group by posting there

Answer 7

dude physics,chemistry involves mathematics that doesnt mean u post it in the math portion

Answer 8

if you must know it follows this \[\frac{dq}{dt} + (\frac{1}{RC}) \;q = \frac{E}{R}\]

;)

Answer 9

it's not physics

Answer 10

it needs to be solved by calculus not physics

Answer 11

go to physics section.

Answer 12

*facepalm* @Romero

Answer 13

I can't help but just so hba knows, calculus has applications in all the branches of science, chemistry, physics, biology, that'ts why calculus is so useful.

To solve this physics problem, one must use calculus.

Answer 14

but it's DIFFERENTIAL EQUATIONS

Answer 15

That's not the same

Answer 16

and i am aware of the application of calculus

Answer 17

Most calculus textbooks will have examples involving the other branches..but yeah, i hope someone can help you out @igbasallote

Answer 18

it's an application of differential equation

Answer 19

post it in the physics portion ill give it a try

Answer 20

Is this from a differential equation class or a physics class?

Answer 21

it's a differential equations class

Answer 22

i wouldnt post it here if it was from a physics class now would i

Answer 23

Have you had physics before?

Answer 24

no

Answer 25

well not this kind

Answer 26

i just know calculus

Answer 27

Why would your professor give you a question like this. In all the real life diff eq problems that I did we had to know some previous knowledge of that field in order to set it up...

Answer 28

i dont know..it's application of first order differential equations..that's our lesson...why wouldnt he

Answer 29

i = dq/dt, the rate of change of charge with respect to time.

Answer 30

fine. i'll post this in physics. but it really is just an application of firs order diff eq -_-