Assignment pend_01

Count the number of complete cycles completed by a pendulum of length 10 cm in 15 seconds. 

• The length of a pendulum is measured from the point where it is held to the center of the mass at the end of the string. 
• A pendulum oscillates between two extreme points. 
• A cycle runs from an extreme point through the 'middle' or equilibrium point to the opposite extreme point, then back through the equilibrium point to the original extreme point. 
• Allow the pendulum to swing gently.

Repeat for a length of 20 cm.

Repeat for a length of 40 cm.

The number of cycles for the 10 cm pendulum will be Item 1, the number for the 20 cm pendulum will be Item 2 and the number for the 40 cm pendulum will be Item 3.

For each length figure out how long it took to complete each cycle, on the average.  Give your results rounded to the nearest hundredth of a second.  The time required for a complete cycle is called the period of the pendulum.  The period of the 10 cm pendulum will be Item 4, the period of the 20 cm pendulum will be Item 5 and the period of the 40 cm pendulum will be Item 6.

Use a reasonable scale with the figure below to sketch a graph of the period of a pendulum vs. its length, with the period being the y coordinate and the length being the x coordinate.

Sketch the straight line or smooth curve you think best fits the figure.

As Item 7, discuss whether the best graph would be a straight or curved line, and whether you think the graph is curving up or curving down.

Use your curve to make your best estimate of the period of a pendulum whose length is 30 cm.  Your estimate will be Item 8.

Use your curve to make your best estimate of the length of a pendulum whose period is .5 second.  Your estimate will be Item 9.

As Item 10, use the pattern of your results as best you can to estimate the period of a pendulum of length 80 cm.