If the temperature is zero outside today and it's going to be twice as cold tomorrow, how cold will it be?

Answer 1

Q: My teacher asked us: "It's zero degrees outside and tomorrow it's going to be twice as cold. What will the temperature be?"

A: We get this question often, which makes me think it must be on some sort of lesson plan. The first thought might be to change the zero into the other common scale, which rids you of the troublesome "zero." Assuming the teacher means zero Fahrenheit, the same temperature is minus 17.7 degrees Celsius. If the zero is Celsius, changing it to Fahrenheit gives you 32 degrees.

The answer would be simple if the teacher had said, "tomorrow it will be zero and tomorrow the temperature will be twice as low, what will it be?" To this question, we could answer "minus 35.4 degrees C, which is the same as -31.7 F."

But, the teacher said "it's going to be twice as cold," and that is something completely different and more complicated. Stop and ask, "What are we talking about here?"

The way this question is posed means you "should focus on the issue of heat (energy)," Bob Weinbeck of the American Meteorological Society's Education Office said when we sent the question to the AMS. "Cold is really the presence of minimal heat. Temperature only reflects the amount of heat - and on an arbitrary scale. One could use the absolute temperature scale."

By "absolute temperature scale" Weinbeck means a scale that begins at absolute zero; that is at the temperature at which there is no molecular motion. For more on this, see the USATODAY.com graphic that explains how temperature is really a measurement of molecular motion. The most common absolute scale is the Kelvin (K) scale, which is based on the Celsius scale with minus 273.16 degrees C being 0 degrees K. To change C to K, just add 273.16 degrees to the C reading. If you have learned algebra, you know that -17.7C will be 255.46 degrees K. (Since -17.7 is a negative number you subtract it from 273.16 when you add the two.)

Our converting between temperature scales page has more on the different scales.

Once you have converted to the Kelvin scale you're ready to figure out what twice as cold means. "Twice as cold would mean only half the heat energy," Weinbeck says. "So that the absolute temperature would be half of 255.46 K or 127.73 K. Such temperatures would certainly shiver your timbers!"

To see how much it would shiver your timbers, convert back to Celsius. Since you added 273.16 to the Celsius temperature to get the Kelvin temperature, you'd do the opposite to go the other way. That is, subtract 273.16 from 127.73 K to get the Celsius temperature of minus 145.43 degrees. This is a lot colder than the world record cold of minus 89.6 degrees C. set July 21, 1983 at the Russian Vostok Station in Antarctica. If tomorrow is really going to be that cold, the sun must be dying.

I'm curious, and I'm sure Weinbeck and his colleagues at the American Meteorological Society are also wondering, whether this is the "right" answer the teacher is looking for. If not, we'd love to hear what the "right" answer is and how it was obtained.

Normally we don't give answers to homework questions in as much detail as we have here. We prefer to point students in the right direction and let them find the answers. But, I think that this question doesn't offer much to students who don't already understand the nature of heat and temperature and the concept of absolute zero. I guess it could be a lead in to such a discussion. Teachers who use questions such as this one might want to check out the kinds of help the American Meteorological Society can offer them in using weather in the classroom.

Answer 2

OK, let's think logically. If it's zero outside, assuming that you using the US guage which uses Farenheit. So lets make some reasoning statements to arrive at the logical answer to your question, shall we?

If water freeze at 32 (you see I have to use some form of reference, in order to arrive at the answer in a logical manner and yet presentable) and the temperature is zero outside right now. someone claimed that it will be twice as cold. Taking this information into account, we have zero degrees which is -32 degrees from the freeing temperature for water.

So then, (0 - 32) + (-32) = X, Then X= -64. My God tomorrow is going to be -64 which is twice as cold at zero.

Answer 3

It will be -228 F, if you are talking about Fahrenheit degrees; halfway from zero to absolute zero. That is twice as cold.

Answer 4

Sub Zero?

Answer 5

-2

Answer 6

It still be zero degress, because zero can be taken from zero. Sounds like a trick question to me.

Answer 7

-2

Answer 8

Too cold to go out
stay indoors under the duvet

Answer 9

Quality....Still Zero I would imagine.

Answer 10

-18