Question

A mercury thermometer records a temperature of 8 degrees Fahrenheit at 10:00am.If the Temperature drops by 3 degrees Fahrenheit every hour,what will be the Temperature by 2:00pm of the same day

Answer 1

Given:

Temperature at 10:00 am = 8 degrees Fahrenheit

Temperature drops by 3 degrees Fahrenheit every hour.

To find:

The temperature by 2:00pm of the same day.

Solution:

Let y be the temperature after x hour after 10:00 am.

The temperature at 10:00 am is the initial temperature.

So, y-intercept of the linear function is 8.

Temperature drops by 3 degrees Fahrenheit every hour.

So, slope of linear function is -3. Here, negative sign represents the decrease in the temperature.

Slope intercept form of a linear function is

$y=mx+b$

where, m is slope and b is y-intercept.

Substitute m=-3 and y=8 in the above equation.

$y=-3x+8$

Difference between 2:00pm and 10:00 am is 4 hours. So, substitute x=4 in the above equation.

$y=-3(4)+8$

$y=-12+8$

$y=-4$

Therefore, the temperature by 2:00pm of the same day is -4 degrees Fahrenheit.