How does pendulum

Example 1. Measuring Acceleration due to Gravity: The Period of a Pendulum What is the acceleration due to gravity in a region where a simple pendulum having a length Strategy We are asked to find g given the period T and the length L of a pendulum.

Discussion This method for determining g can be very accurate. Making Career Connections Knowing g can be important in geological exploration; for example, a map of g over large geographical regions aids the study of plate tectonics and helps in the search for oil fields and large mineral deposits. Take Home Experiment: Determining g Use a simple pendulum to determine the acceleration due to gravity g in your own locale.

Check Your Understanding An engineer builds two simple pendula. Solution The movement of the pendula will not differ at all because the mass of the bob has no effect on the motion of a simple pendulum. PhET Explorations: Pendulum Lab Play with one or two pendulums and discover how the period of a simple pendulum depends on the length of the string, the mass of the pendulum bob, and the amplitude of the swing.

Click to run the simulation. Suppose you move from one city to another where the acceleration due to gravity is slightly greater, taking your pendulum clock with you, will you have to lengthen or shorten the pendulum to keep the correct time, other factors remaining constant? Explain your answer. What is the length of a pendulum that has a period of 0.

Some people think a pendulum with a period of 1. True or not, what is the length of such a pendulum? What is the period of a 1. How long does it take a child on a swing to complete one swing if her center of gravity is 4.

The pendulum on a cuckoo clock is 5. And now that you know a little bit more about pendulums, we bet that by exploring yourself, you will find your answers hidden in your own subconscious! After all, you are magical! The magic was always you! Want to learn more about Pendulums, here are some of our favorite articles!

The Ultimate Pendulum Guide. Building your Intuition. How to Choose a Pendulum? Questions to Ask Your Pendulum. More Posts. Read More. Astro Alerts Astro Alert: Mercur About Who Are We? Will I have more fun in the mountains or at the beach? Do I want to go to Mexico or Alaska? Making a choice or decision: Do I want to go to the movies? Do I want really to take French this year? You are probably wondering which pendulum would be right for you. The simple answer is to use the one that you feel is right at the time.

In other words, make sure it appeals your inner child, your intuition, and your subconscious. Now the thing is that you will find your intuition will tell you to use different ones at different times.

For example people will seem to want to use a red or pink crystal when making decisions affecting the heart, like picking a mate, deciding on going on a date, or deciding if someone will be the only boyfriend. I f you had questions about a decision and you were concerned with safety, you might be drawn to a black crystal.

Black crystals have protection energy. Maybe you are just examining your creativity and wonder if you should take up painting. You might well be drawn to a Amethyst.

We can only advise exploration. Try some and see how they work and how they respond. Do a little more research, practice, and amaze yourself. You must be logged in to post a comment. This site uses Akismet to reduce spam. Learn how your comment data is processed. Answer a few simple questions and we can tell you what crystal would help you most right now.

Pendulum Guide — Easy, and Amazing Steeped in ancient lore and legend, the simple, but amazing tool, the pendulum is still in use today. We are often asked: What is a pendulum, exactly? How does it a pendulum work? Really, does it work at all or is it just a trick? And if they do somehow really work, what does a pendulum do?

More importantly, can I make it work? What can I use a pendulum for? Where are my keys? As it does, its height is increasing as it moves further and further away. It reaches a maximum height as it reaches the position of maximum displacement from the equilibrium position. As the bob moves towards its equilibrium position, it decreases its height and decreases its potential energy.

Now let's put these two concepts of kinetic energy and potential energy together as we consider the motion of a pendulum bob moving along the arc shown in the diagram at the right. We will use an energy bar chart to represent the changes in the two forms of energy. The amount of each form of energy is represented by a bar. The height of the bar is proportional to the amount of that form of energy.

The TME bar represents the total amount of mechanical energy possessed by the pendulum bob. The total mechanical energy is simply the sum of the two forms of energy — kinetic plus potential energy. What do you notice?

When you inspect the bar charts, it is evident that as the bob moves from A to D, the kinetic energy is increasing and the potential energy is decreasing. However, the total amount of these two forms of energy is remaining constant. Whatever potential energy is lost in going from position A to position D appears as kinetic energy. There is a transformation of potential energy into kinetic energy as the bob moves from position A to position D. Yet the total mechanical energy remains constant.

We would say that mechanical energy is conserved. As the bob moves past position D towards position G, the opposite is observed. Kinetic energy decreases as the bob moves rightward and more importantly upward toward position G. There is an increase in potential energy to accompany this decrease in kinetic energy. Energy is being transformed from kinetic form into potential form. Yet, as illustrated by the TME bar, the total amount of mechanical energy is conserved. This very principle of energy conservation was explained in the Energy chapter of The Physics Classroom Tutorial.

Our final discussion will pertain to the period of the pendulum. As discussed previously in this lesson , the period is the time it takes for a vibrating object to complete its cycle.

In the case of pendulum, it is the time for the pendulum to start at one extreme , travel to the opposite extreme , and then return to the original location. Here we will be interested in the question What variables affect the period of a pendulum?

We will concern ourselves with possible variables. The variables are the mass of the pendulum bob, the length of the string on which it hangs, and the angular displacement. The angular displacement or arc angle is the angle that the string makes with the vertical when released from rest. These three variables and their effect on the period are easily studied and are often the focus of a physics lab in an introductory physics class.

The data table below provides representative data for such a study. In trials 1 through 5, the mass of the bob was systematically altered while keeping the other quantities constant. By so doing, the experimenters were able to investigate the possible effect of the mass upon the period. As can be seen in these five trials, alterations in mass have little effect upon the period of the pendulum.

In trials 4 and , the mass is held constant at 0. However, the length of the pendulum is varied. By so doing, the experimenters were able to investigate the possible effect of the length of the string upon the period. As can be seen in these five trials, alterations in length definitely have an effect upon the period of the pendulum.

As the string is lengthened, the period of the pendulum is increased. There is a direct relationship between the period and the length. Finally, the experimenters investigated the possible effect of the arc angle upon the period in trials 4 and The mass is held constant at 0.

As can be seen from these five trials, alterations in the arc angle have little to no effect upon the period of the pendulum. So the conclusion from such an experiment is that the one variable that effects the period of the pendulum is the length of the string. Increases in the length lead to increases in the period. But the investigation doesn't have to stop there. The quantitative equation relating these variables can be determined if the data is plotted and linear regression analysis is performed.

The two plots below represent such an analysis. In each plot, values of period the dependent variable are placed on the vertical axis.

In the plot on the left, the length of the pendulum is placed on the horizontal axis. The shape of the curve indicates some sort of power relationship between period and length.

The results of the regression analysis are shown. The analysis shows that there is a better fit of the data and the regression line for the graph on the right.