Why does length affect a pendulum

In that case the swing rate will be affected as the pendulum goes faster. One factor that does not affect swing rate is the weight of the bob. Increase the weight on the pendulum and gravity just pulls harder, evening out the extra weight. As School for Champions points out, the force of gravity on any falling object is the same no matter what the object's mass.

In a real-world application air resistance affects the swing rate. Each swing encounters that resistance and it slows down the swing, although it might not be enough to be noticeable during one swing. Friction also slows down the swing. If the pendulum is swinging based upon inertia from the initial release eventually it will come to a stop.

The swing rate of a pendulum adjusts when placed in close proximity to another pendulum. This phenomenon is called sympathetic vibration. The pendulums pass motion and energy back and forth.

This transfer will eventually cause the swing rate of one pendulum to be identical with that of the other pendulum. Robert Alley has been a freelance writer since He has covered a variety of subjects, including science and sports, for various websites. What Affects the Swing Rate of a Pendulum? Different Types of Pendulums. A pendulum with a longer string has a lower frequency, meaning it swings back and forth less times in a given amount of time than a pendulum with a shorter string length.

This makes that the pendulum with the longer string completes less back and forth cycles in a given amount of time, because each cycle takes it more time. The mass of the bob does not affect the period of a pendulum because as Galileo discovered and Newton explained , the mass of the bob is being accelerated toward the ground at a constant rate — the gravitational constant, g.

Just as objects with different masses but similar shapes fall at the same rate for example, a ping-pong ball and a golf ball, or a grape and a large ball bearing , the pendulum is pulled downward at the same rate no matter how much the bob weighs. Finally, the angle that the pendulum swings through a big swing or a small swing does not affect the period of the pendulum because pendulums swinging through a larger angle accelerate more than pendulums swinging through a small angle.

This is because of the way objects fall; when something is falling, it keeps accelerating. As long as an object is not going as fast as it can, it is speeding up.

Therefore, something that has been falling longer will be going faster than something that has just been released. A pendulum swinging through a large angle is being pulled down by gravity for a longer part of its swing than a pendulum swinging through a small angle, so it speeds up more, covering the larger distance of its big swing in the same amount of time as the pendulum swinging through a small angle covers its shorter distance traveled.

Watch this activity on YouTube. Ask the students to explain which factors might affect the period of a pendulum. Answer: Pendulum length, bob weight, angle pendulum swings through. Which factor s really do affect the pendulum's period? Answer: The length of the pendulum. Why does the weight not make a difference?

Answer: Because the pendulum, just like falling objects, is not dependent on weight. How does the length of a pendulum's string affect its period? Answer: A pendulum with a longer string has a longer period, meaning it takes a longer time to complete one back and forth cycle when compared with a pendulum with a shorter string. Also, the pendulum with the longer string has a lower frequency, which means it completes less back and forth cycles in a given amount of time as compared with a pendulum with a shorter string.

Why does the angle the pendulum starts at not affect the period? Answer: Because pendulums that start at a bigger angle have longer to speed up, so they travel faster than pendulums that start at a small angle. One oscillation is complete when the bob returns to its starting position.

Count the votes and write the totals on the board. Give the right answer. Human Matching: On ten pieces of paper, write either the term or the definition of the five vocabulary words. Ask for ten volunteers from the class to come up to the front of the room, and give each person one of the pieces of paper. One at a time, have each volunteer read what is written on their paper. Have the remainder of the class match term to definition by voting.

Have student "terms" stand by their "definitions. As a library research project, have the students research Galileo Galilei. What other scientific findings did he make during his lifetime? Have the students' research the ways that engineers use pendulums today.

Some suggestions: seismographs, inertial dampeners, in sky-scrapers. Gamow, George. The Great Physicists from Galileo to Einstein. Wolfson, Richard and Jay M. Physics: For Scientists and Engineers. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government. Why Teach Engineering in K?

Find more at TeachEngineering. Quick Look. Print this lesson Toggle Dropdown Print lesson and its associated curriculum. Suggest an edit. Discuss this lesson. Curriculum in this Unit Units serve as guides to a particular content or subject area. Rocket Couch Potato or Inertia Victim? Ring around the Rosie Super Spinners! Similarly the tension in the cord will not affect the pendulum but if change in the length of the pendulum while keeping other factors constant changes the length of the period of pendulum.

There are two major forces that act on a pendulum, the force of gravity and tension force from the string that holds the pendulum. At all points in the trajectory of the pendulum bob, the angle between the force of tension and its direction of motion is 90 degrees.

Thus, the force of tension does not do work upon the bob. Since there are no external forces doing work, the total mechanical energy of the pendulum bob is conserved. The thing you must understand is tension act in the opposite direction of the gravitational force. If your object is hanging it must balanced by tension, otherwise it will accelerate down due to gravity.

If we look at a small section of the rope at its center, it will be pulled into two directions by tension leading away one way along the rope and tension leading away in the other. As you state, these two forces will cancel out. That is only generally applied to forces exerted by a field, like gravity. It is directed along the length of the cable and pulls equally on the objects on the opposite ends of the wire.

Cables and ropes can be used for exerting forces since they can transfer force over a specific distance efficiently.