Golf ball

A golf ball is dropped and a regular strobe light illustrates its motion as follows...

 We observe that it is a parabola.

Problem:What is the equation of the parabola that the golf ball is tracing out?

ΓΙΑ ΤΟΥΣ ΜΑΘΗΤΕΣ: χρησιμοποιήστε το Excel για να σχεδιάσετε το γράφημα.
Use Excel for making the graph and finding out the equation!

We can model the motion from the data points obtained by observing the position (height) of the ball at various times.
This is the table of values time/height:

Source: http://www.intmath.com/Plane-analytic-geometry/4_Parabola.php,  http://wn.com/The_Ball_and_the_Parabola

Also the tennis ball does the same motion. Watch the video:

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Using Excel to Model Curves

You can use Microsoft Excel to module a parabola. After you plot the points, right-click on one of the points and choose "Add Trendline (Γραμμή Τάσης)".
Choose Polynomial, degree 2. In "Options (Μορφοποίηση γραμμής τάσης --> Επιλογές)" you can get Excel to display the equation of the parabola on the chart.

Here it is the excel sheet which the students created

Plot the Graph by Geogebra:

Let's get to have a look at Geogebra file! Click HERE!