| 1E-6 : | Temperature Change & Unit Conversions | 2 pts |
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| The temperature of a cup of water drops by 44oF when it is placed in a refrigerator for 45 minutes. How much did the temperature of the water change in K, oR and in oC. | ||||||||||||
| Read: | The key to this problem is that we are considering a CHANGE in temperature and NOT a temperature of 27oC. | |||||||||||
| Given: | DT | -44 | oF | |||||||||
| Find: | DT | ??? | K | DT | ??? | oC | ||||||
| DT | ??? | oR | ||||||||||
| Assumptions: | None. | |||||||||||
| Equations / Data / Solve: | ||||||||||||
| Start with Rankine. The temperature increments for the Fahrenheit and Rankine scales are the same. Therefore : | ||||||||||||
| DT | -44 | oR | ||||||||||
| Next, let's work on getting DT in the Kelvin scale. | ||||||||||||
| This is straightforward because a temperature change of 1 K is equal to a temperature change of 1.8 oR. | ||||||||||||
|
Eqn 1 | |||||||||||
| DT | -24.444 | K | ||||||||||
| Finally, the temperature increments for the Celsius and Kelvin scales are the same. | ||||||||||||
| Therefore : | DT | -24.444 | oC | |||||||||
| Answers: | DT | -24.4 | K | |||||||||
| DT | -44 | oR | ||||||||||
| DT | -24.4 | oC | ||||||||||
