lilaznjewel

## Homework Statement

At 30.3C, the resistance of a segment of gold
wire is 124.9 omega When the wire is placed in a
liquid bath, the resistance decreases to 97.5 omega
What is the temperature of the bath?
The temperature coefficient for gold is
0.0034 (C)−1 at 20C.
Answer in units of C.

## Homework Equations

used R=Ro[1+alpha(t-to)

## The Attempt at a Solution

I got -34.2, but the hw says its incorrect

## Answers and Replies

Mentor
Hmm. The numbers look okay to me. Did you include the units when you answered?

lilaznjewel
Hmm. The numbers look okay to me. Did you include the units when you answered?

yes do you think it could be wrong because of sigfigs so it be -34.22

Mentor
How many significant figures do each of the provided numbers have?

lilaznjewel
To has 3
Ro has 4
R has 3
alpha has 4

Mentor
Check http://www.usca.edu/chemistry/genchem/sigfig.htm" [Broken].

Last edited by a moderator:
lilaznjewel
ok i put in -34.22 but, it is still wrong

Mentor
-34.22 has four significant figures. The temperature coefficient has fewer.

cupid.callin
I'm getting something else ... its less than your answer

why not use the temp you got and find the resistance and match it with 124.9 ohm

lilaznjewel
I don't really understand what you are trying to say

Mentor
The provided temperature coefficient for gold has two significant figures. Did you try your result with two significant figures?