Question

Please help! The power, p, produced by an electrical circuit varies directly as the square of the voltage, V, and inversely as the resistance, R. What equation matches this description?

Answer 1

Alright! Let's do this. :D

Answer 2

BTW: Math rocks! It's fun stuff!

Answer 3

Haha you can help? Omg how can you say that?!

Answer 4

Math lets you understand stuff! For example: I'm guessing you have an ipod. Do you like your ipod?

Answer 5

Haha yes. Yes I do.

Answer 6

It reads like:
\[p=(V ^{2})/R\]
But I didn;t pay attention in my Electrical Engineering :)

Answer 7

Thank you much Osirisis!

Answer 8

They used the power formula to know how to safely power your ipod. Along with tons of other math. Without math, you wouldn't have your ipod!

Answer 9

Mathsux: The problem is you just got an answer but have no idea how you got the answer. Of course math is going to suck if you just cheat. :(

Answer 10

Do you wish to learn HOW to get the right answer?

Answer 11

Well I just hate doing it... They can have other people like YOU who can do it :P And yes please do. I would like to learn.

Answer 12

Well, I hated algebra when I was younger, because my teacher was horrible. But with some practice, I taught myself how to do it. Nothing fancy. Just requires that you ask questions when needed. ALright, so on to solving this problem:

Answer 13

I'm guessing by your hatred of math, you don't remember what the teacher said about inverse proportions and direct proportions. Do you know what the difference is?

Answer 14

Inverse: product of the variables is constant... Direct: y varies directly with x if there is a non zero constant k. (My keyboard is going super slow for some odd reason.)

Answer 15

Ok, that's the textbook definition. But in "human" language, can you tell me what it means?

Answer 16

Ahaha... Got me there :)

Answer 17

Ok, good. It's more important that you understand what it means than what it's "defined" as.

Alright, here we go:

Answer 18

"The amount of money made is directly proportional to $4 times the number of tickets sold".

If n = number of tickets sold, and y = amount of money I made, how would this equation look?

Answer 19

Directly proportional means "If I raise my n value, then my y value also gets raised through multiplication". It kinda means that for the most part.

Answer 20

y=4n?

Answer 21

perfect!
So it's just multiplication, right?

Answer 22

Exactly! Now I see. :)

Answer 23

Alright, so here's what inverse proportions are:

"A house costs $1000 to rent every month. The total never changes from $1000. However, the more roommates there are, the less each one has to pay for their share. For example, two roommates would pay $500 each. Four roommates would pay $250. Ten roommates would pay $100 a piece."

Answer 24

How do we find out how much each person pays if y = how much each person pays, and n = how many people there are?

Answer 25

n*y?

Answer 26

n*y?

Well, look at it: If we have 10 people, then we have: 10(y), or 10y. Does 10y tell us anything?

Answer 27

For one thing, we don't even have an equals sign in there. So it's not even a solveable equation.

Answer 28

Second problem is you never even touched the $1000

Answer 29

Think of it in real life terms: If I told you I found 1000, how would we figure out how to share it equally?

Answer 30

Divide

Answer 31

Excellent! So what are we dividing by what?

Answer 32

Total amount by number of people.

Answer 33

excellent! So 1000 / n = y, yes?

Answer 34

Hmmm makes sense! :) THANKS!

Answer 35

Awesome, no prob. But before we finish, I want you to solve the original equation. No cheating!

Answer 36

How do you say that "P is directly proportional to the SQUARE of V"?

Answer 37

Gave up?