Part 4:Graphing Daylight Data

Rather than work with data sets with 365 elements, we will collect the data for sunrise and sunset once each week.  Remember, you can find the sunrise/sunset data from the U. S. Naval Observatory web site, but you will need to convert the hours and minutes to decimal hours.

Your Assignment:

1.  Enter a location on the U. S. Naval Observatory web site and collect the sunrise/sunset data for every seventh day of the year.  The web site does not contain information for Coventry, specifically, but it does contain information for such nearby locations as Storrs and Willimantic.

2.  Make a chart of the data, as follows.  Please do NOT covert any times to Daylight Savings Time.  Include a running tally of the "Day #" in the second column, that is, how many days since the start of the year.
 

3. Compute the number of hours of daylight for the first day of each month and enter this value into the last column.

4. Make a scatter plot of this data.  (Extend the graph for a 3-year time period).  Be sure to graph the "Date" (or "Day #") as the x-value and "daylight Hours" as the y-value.
 
 
 
 

To convert hours and minutes to decimal hours, you can reason as follows:

There are 60 minutes in an hour, so each minute is 1/60 of an hour.  So two minutes would be 2/60, and so on.  Therefore, you can convert any number of minutes to hours by dividing by 60.

Example:  24 minutes  =  24/60 hours,  or 24 divided by 60,  which equals .4

If you have both hours and minutes, then compute the decimal equivalent, as above, then add the decimal to the whole number of hours.

Example:  5:36 (five hours and 36 minutes)  =   5 + 36/60   =   5 + .6   =   5.6