Timing is Everything

Wrap-up Worksheet

Name: _________________________________________

Date: ______

Class: _______________________

Today you examined the behavior of a simple pendulum. Fill out this worksheet with the results of your experiments. Each student is responsible for completing this worksheet.

1. We say that the pendulum undergoes periodic motion, where periodic motion, cycle and period are defined below.

   periodic motion: motion that repeats itself in the same amount of time
   cycle: one repetition of periodic motion
   period: the time it takes to complete one cycle

   Describe in words and with a diagram what one cycle would be for the pendulum.

2. Create a line plot of amplitude of each swing versus mean time it takes to make that swing on your own graph paper.

3. Once you plot the data you have the "picture" of the period. What is your guess of the time for that period?
4. How would the results be different if instead of a string 30 cm long, we used 10 cm string?
5. How would the results be different we used a string 100 cm long?
6. Summarize the relationship that you may see with time or swings and the use of different length string.
7. 7. This relationship between the time and the different length of string is actually defined by certain laws of physics. These laws let us say that the period is equal to:
   

   Where g is the acceleration due to gravity (here on Earth it has a value of 9.8 m/sec².), L is the length of the pendulum string from where it is tied at the top to where the center of mass is of the tied object, and π = 3.14.

   Does your guessed period in question 3 confirm this? Prove this by showing your work below.