# A temp change of 20 degrees C

Dx
A temp change of 20 degrees C corresponds to a temp change of

68degrees F

i got this one wrong? whats up with that???

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dav2008
Gold Member
Well, its asking for a change...

20 deg C=68 deg F...but...

Lets say the change in C is from 0 to 20, then the change in F is from 32 to 68, giving your answer of (68-32)=36

HallsofIvy
Homework Helper
Water freezes at 32 degrees F= 0 degrees C
Water boils at 212 degrees F= 100 degrees C
so that 212-32= 190 degrees F spans as much as 100 degrees C so each degree C corresponds to 190/100= 1.9 degrees F.

A change of 20 degrees C corresponds to a change of 20(1.9)= 38 degrees F.

(Or, you could have argued that 20 degrees C is 1/5 of the way from freezing to boiling and so corresponds to (212-32)/5= 190/5= 38 degrees F.

(Oh, by the way, a temperature of 20 degrees C is 70 degrees F, not 68. The general formula is F= 1.9C+ 32.

Dx
Originally posted by HallsofIvy
Water freezes at 32 degrees F= 0 degrees C
Water boils at 212 degrees F= 100 degrees C
so that 212-32= 190 degrees F spans as much as 100 degrees C so each degree C corresponds to 190/100= 1.9 degrees F.

A change of 20 degrees C corresponds to a change of 20(1.9)= 38 degrees F.

(Or, you could have argued that 20 degrees C is 1/5 of the way from freezing to boiling and so corresponds to (212-32)/5= 190/5= 38 degrees F.

(Oh, by the way, a temperature of 20 degrees C is 70 degrees F, not 68. The general formula is F= 1.9C+ 32.
Thanks for the info Ivy and dav2008.
BTW...9/5 = 1.8C + 32 not 1.9 and my answer of 68 degrees is right.

Thanks!

Dx 