Question

The temperature falls from 0 degrees to -12 1/4 degrees in 3 1/2 hours. Which expression finds the change in temperature per hour?

Answer 1

Answer:

Change in temperature per hour = 3.5°C/hr

Step-by-step explanation:

The temperature falls from 0 degrees to -12 1/4 degrees in 3 1/2 hours.

Change in temperature,

                 $\Delta T=0-\left ( -12\frac{1}{4}\right )=0+\frac{12\times 4+1}{4}=\frac{49}{4}$

Time taken

                $t=3\frac{1}{2}=\frac{3\times 2+1}{2}=\frac{7}{2}hours$

$\texttt{Change in temperature per hour}=\frac{\Delta T}{t}=\frac{\frac{49}{4}}{\frac{7}{2}}=\frac{98}{28}\\\\\texttt{Change in temperature per hour}=\frac{49}{14}=\frac{7}{2}=3.5^0C/hr$

Change in temperature per hour = 3.5°C/hr        

Answer 2

Answer:

-7/2 degrees per hour

Step-by-step explanation:

Divide the total change (-12 1/4 degrees) by the total time elapsed (3 1/2 hrs):

-49/4 degrees          -49(2)

------------------------ = ------------- = -7/2 degrees per hour

    7/2 hrs                   4(7)