Question

On January 22 in 1943, the town of Spearfish, South Dakota, set the record for the world's fastest temperature changeAt 7:30 a.m., the temperature was -4°FBy 7:32 a.m., the temperature was 45°F.By 9:00 am the same day, the temperature was 54°F.By 9:27 a.m., the temperature was -4°F.How many degrees did the temperature change each minute from 7:30 to 7:322O 49 per minuteO 11.25 per minute24.5 per minute20.5 per minute1

Answer 1

Step 1

The slope is calculated by finding the ratio of the "vertical change" to the "horizontal change" between (any) two distinct points on a line. Sometimes the ratio is expressed as a quotient ("rise over run"), giving the same number for every two distinct points on the same line.

The slope is given as;

`m=\frac{rise}{\text{run}}=(y_2-y_1)/(x_2-x_1)`

Step 2

From 7:30 a.m to 7:32a.m the temperature change each minute will be;

`\begin{gathered} y_2=45 \\ y_1=-4 \\ x_1=0 \\ x_2=2 \end{gathered}`
`\begin{gathered} m=(45-(-4))/(2-0) \\ m=(45+4)/(2)=(49)/(2)=24.5 \end{gathered}`

Therefore, between, 7:30 a.m to 7:32a.m the temperature change each minute is 24.5 per minute