Final answer:
The temperature change per hour when the temperature fell from 0°F to 6 3/5°F below 0°F in 2 1/5 hours is 3°F per hour.
Step-by-step explanation:
The question asks about the rate of temperature change per hour when the temperature fell from 0°F to 6 3/5 degrees Fahrenheit below 0°F over a period of 2 1/5 hours. To find the rate of temperature change per hour, we divide the total change in temperature by the total time period.
First, let's convert the mixed numbers to improper fractions:
- The temperature change is 6 3/5 °F, which is equal to (6 * 5 + 3)/5 = 33/5 °F.
- The time period is 2 1/5 hours, which is equal to (2 * 5 + 1)/5 = 11/5 hours.
Now, we calculate the temperature change per hour:
Temperature change per hour = (Total temperature change) / (Total time)
Temperature change per hour = (33/5 °F) / (11/5 hours) = (33/5) × (5/11) °F/hour
After simplifying, we get:
Temperature change per hour = 3 °F/hour
Therefore, the correct answer is 3 degrees Fahrenheit per hour.