Given:
From 1:00 pm to 3:30 pm the room temperature had dropped from 82F to 72F.
To find:
The average rate of change of temperature in this room over the period.
Solution:
Time between 1:00 pm to 3:30 pm is 2 hr 30 minutes, i.e., 2.5 hours.
So, change in time is 2.5 hours.
Room temperature had dropped from 82F to 72F.
Change in temperature = 72 F - 82 F
= -10 F
We know that, average rate of change of temperature in this room over the period is
[tex]m=\dfrac{\text{Change in temperature}}{\text{Change in time}}[/tex]
[tex]m=\dfrac{-10}{2.5}[/tex]
[tex]m=-4[/tex]
Therefore, the average rate of change of temperature in this room over the period is -4. It means the temperature is decreasing 4 F per hour.
