SOLUTION: The current I in an electrical conductor varies inversely as the resistence R of the conductor. The current is 2 amperes when the resistance is 501 ohms. What is the current when t

Algebra ->  Equations -> SOLUTION: The current I in an electrical conductor varies inversely as the resistence R of the conductor. The current is 2 amperes when the resistance is 501 ohms. What is the current when t      Log On


   

Question 426029: The current I in an electrical conductor varies inversely as the resistence R of the conductor. The current is 2 amperes when the resistance is 501 ohms. What is the current when the resistance is 844 ohms? round to the nearest tenth if necessary.
Found 2 solutions by josmiceli, Theo:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Use constant of proportionality, k
+I+=+k%2A%281%2FR%29+
given:
+2+=+k%2A%281%2F501%29+
+k+=+2%2A501+
+k+=+1002+
When +R+=+844+
+I+=+k%2A%281%2F844%29+
+I+=+1002%2A%281%2F844%29+
+I+=+1.187+ amps

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
inverse relationship is given by y = k/x

replace y with I and replace x with R to get:

I = k/R

first you want to find out what k is.

use the givens to do that.

when I = 2 amperes, the resistance is 501 ohms.

formula becomes:

2 = k/501

from this, we get k = 2*501 = 1002

now that we have k, we can solve for the I or R, whichever comes first.

When resistance is 844 ohms, the formula becomes:

I = 1002 / 844

this gets us I = 1.187203791 amperes.

if we did not use k, we could have solved using ratios.

in a direct relationship I1/I2 = R1/R2

in an inverse relationship I1/I2 = R2/R1

we were given I1, R1, and R2.

we plug into the equation to get:

2/I2 = 844/501

we cross multiply to get:

844*I2 = 501*2

we divide both sides by 844 to get:

I2 = 2*501/844 = 1.187203791

either way gets you the same answer as long as you do each one the way that is supposed to be done.