Go to the University of Colorado - Boulder PhET website/Pendulum Lab. Conduct four experiments with a 1 kg mass and a 10 pull-back angle from the vertical as controlled variables. The pendulum lengths should be between 0.250 m to 2.500 m, inclusive. Using the photogate timer, determine the period of the pendulum, in seconds.

The studied planet is ___________________. Theoretical value of g for the planet___________

Table 1. Relationship between the Length, l (m), and the Period of the Pendulum, T, (s).

	Experiment #1	Experiment #2	Experiment #3	Experiment #4
String Length (m)
Period, T (s)

1. Using the data in Table 1, find the product between the string length and 4² and record it in the first row of Table 2, below.
2. Calculate the square of the periods on Table 1 in the second row of Table 2, below.

Table 2. Relationship between the String Length, l (m), and the Square of the Period of One Oscillation of a Pendulum, T², (s²).

	Experiment #1	Experiment #2	Experiment #3	Experiment #4
String Length times 42 (m)
Square of the Period (s2)

1. At small angles, , the Period of a Pendulum, T, and the length of the string, l, are related by the formula:

T² = 4²l/g, where g is the acceleration by gravity.

Rearranging the equation, 4²l = g T²

1. With your graphing calculator, enter T² as L₁ and 4²l as L₂. Build a graph with L₁ as the abscissa (x-axis), and L₂ as the ordinate (y-axis). Otherwise, use an Excel spreadsheet as a data table and make a graph. linear regression. The average value of g is the slope of the line, in m/s².

1. What is the experimental average value of the determined g for the planet ________________?

1. Compare your experimental and theoretical values.

1. Repeat the experiment for planet X and determine the value of g for planet X___________