Efficiency of Pendulum: Factors Affecting Amplitude

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In summary, the efficiency of a pendulum's amplitude can be affected by several factors, such as the density of the pendulum bob and the length of the string. A high density bob reduces air drag damping and a longer string reduces the pendulum's frequency, both contributing to greater efficiency. Another interesting experiment is to have two pendula mounted together, where energy will eventually transfer from one to the other. This was demonstrated by a friend who built a grandfather clock and noticed the winding weight chain swinging in unison with the pendulum.
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My project is to build an efficient pendulum that hold 75% of its amplitudeafter 1 minute. What are some things that affects how efficient its amplitude?
 
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anyone help?
 
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I think a high density pendulum bob is important, because it will reduce the air drag damping per unit mass. Note that the mass scales as the 3/2 power of the cross sectional (drag) area, so high mass also helps. A long string will reduce the pendulum frequency, which will also reduce the damping. Note that pendula in clocks are pancake-shaped for a reason (to reduce air drag). An interesting experiment is to have two nearly identical pendula mounted on the same frame. If only one is initially swinging, eventually most of the energy will transfer to the second one (coupled oscillator).
A friend of mine built a grandfather clock, and when it was assembled, started it up in his living room, on a soft hi-pile rug. He was puzzled when the winding weight chain started swinging in unison (or in phase quadrature) with the pendulum.
Bob S
 

1. What is a pendulum and how does it work?

A pendulum is a simple mechanism that consists of a weight, called the bob, attached to a rod or string. When the bob is displaced from its resting position and released, it will swing back and forth in a regular pattern called an oscillation. This motion is due to the force of gravity acting on the bob and the conservation of energy principle.

2. What factors affect the amplitude of a pendulum's swing?

The amplitude of a pendulum's swing is affected by several factors. These include the length of the pendulum, the mass of the bob, the angle at which it is released, and the presence of air resistance or friction. Changes in any of these factors can alter the amplitude of the pendulum's swing.

3. How does the length of a pendulum affect its efficiency?

The length of a pendulum has a direct effect on its efficiency. According to the law of the pendulum, the period of a pendulum (the time it takes to complete one swing) is directly proportional to the square root of its length. This means that a longer pendulum will have a longer period, and therefore, a slower swing. This slower swing results in a smaller amplitude and lower efficiency.

4. How does air resistance affect the efficiency of a pendulum?

Air resistance or friction can decrease the efficiency of a pendulum by dissipating the energy of the pendulum's swing. As the pendulum swings back and forth, it encounters air resistance, which causes it to lose energy. This results in a shorter period and smaller amplitude, leading to a decrease in efficiency.

5. Can the mass of the bob affect the efficiency of a pendulum?

Yes, the mass of the bob can affect the efficiency of a pendulum. According to the law of the pendulum, the period of a pendulum is directly proportional to the square root of its length and inversely proportional to the square root of its mass. This means that a heavier bob will have a shorter period, resulting in a smaller amplitude and lower efficiency compared to a lighter bob.

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