The Naked Scientists
Toggle navigation
Login
Register
Podcasts
The Naked Scientists
eLife
Naked Genetics
Naked Astronomy
In short
Naked Neuroscience
Ask! The Naked Scientists
Question of the Week
Archive
Video
SUBSCRIBE to our Podcasts
Articles
Science News
Features
Interviews
Answers to Science Questions
Get Naked
Do an Experiment
Science Forum
Ask a Question
About
Meet the team
Our Sponsors
Contact us
User menu
Login
Register
Search
Home
Help
Search
Tags
Recent Topics
Lonely Topics
Login
Register
Naked Science Forum
Non Life Sciences
Physics, Astronomy & Cosmology
Any experts know how to solve this problem?
« previous
next »
Print
Pages: [
1
]
Go Down
Any experts know how to solve this problem?
5 Replies
3429 Views
0 Members and 1 Guest are viewing this topic.
alternativess
First timers
4
Activity:
0%
Any experts know how to solve this problem?
«
on:
26/08/2005 20:32:24 »
Logged
David Sparkman
Sr. Member
234
Activity:
0%
Re: Any experts know how to solve this problem?
«
Reply #1 on:
27/08/2005 02:52:11 »
It has been too long and I forgot all the equations, but the above circuit is equalivant to a single 720 ohm resistor. That much I remember.
1/2000 + 1/3000 + 1/1800 = 18/36000 + 12/36000 + 20/36000 = 50/36000. Invert and reduce = 720 ohms total resistance.
David
«
Last Edit: 27/08/2005 02:57:41 by David Sparkman
»
Logged
David
simeonie
Sr. Member
351
Activity:
0%
Re: Any experts know how to solve this problem?
«
Reply #2 on:
27/08/2005 12:03:26 »
OH CRUD! That isn't G.C.S.E work is it? If so I am going to fail because I haven't a clue about all that.
----------------------
...sorry, you cannot view external links. To see them, please
REGISTER
or
LOGIN
Check it out. Click on the forums
Logged
----------------------
MY NAME IS NOT REALLY SIMEONIE IT IS SIMON!!!
David Sparkman
Sr. Member
234
Activity:
0%
Re: Any experts know how to solve this problem?
«
Reply #3 on:
27/08/2005 12:50:28 »
It seems to be rudimentry electricty that I learned in 7th grade, some in class, some just from a book on electricty. Since V=IR and overall resistance is 720 ohms it follows that -30 Volts =i3*720 ohms or I3 = -30/720. Solve for each part of the circuit, and add the amperage to see if everything matches (within rounding error). Lets see that would have been a tough problem for 7th grade algebra. The only thing I don't remember is the power equation. I think it was I^2 * R.
To explain for those who didn't get the first part, resistance in series is addative. Resistance in parellel follows a simple rule of adding the inverse and reinverting.
Say you have a 2 ohm and a 3 ohm resistor in parellel. Most of the current will go though the 2 ohm resistor, but the effect will be a resistance that is lower than both the 2 and the 3 ohms. Take the inverse of each and you get 1/2 and 1/3 and sum them for 5/6. Reinvert the result for your answer of 6/5 or 1.2 ohms resistance.
David
«
Last Edit: 27/08/2005 12:57:34 by David Sparkman
»
Logged
David
alternativess
First timers
4
Activity:
0%
Re: Any experts know how to solve this problem?
«
Reply #4 on:
27/08/2005 16:51:47 »
Thanks David
Logged
gsmollin
Hero Member
749
Activity:
0%
Re: Any experts know how to solve this problem?
«
Reply #5 on:
29/08/2005 16:26:30 »
Alternativess, this is your second circuits question. Are you conning us into doing your homework? Really, that won't help you at exam time.
"F = ma, E = mc^2, and you can't push a string."
Logged
"F = ma, E = mc^2, and you can't push a string."
Naked Science Forum
Re: Any experts know how to solve this problem?
«
Reply #5 on:
29/08/2005 16:26:30 »
Print
Pages: [
1
]
Go Up
« previous
next »
Tags:
There was an error while thanking
Thanking...