A pendulum uses gravity to swing a weight.Pendulums have been used for hundreds of years to keep time.The simplicity of the pendulum is part of its beauty.If you have a few supplies, you can build and use your own pendulum to try out different experiments to see how the physics of a pendulum work.
Step 1: There is a pencil on the top of the table.
Put a pencil on its side and use clear tape to attach it to a table.The pencil should be hung over the edge.If you want to keep your pendulum from falling down, be sure to anchor it with a pencil and use enough tape to secure it.You can test the pencil by flicking it with your finger.It should stay put.
Step 2: At one end of the string, tie a loop about 1 inch in diameter.
Curl one end of the string to form a loop.The loop needs to fit around the pencil, but not too tight or it won't swing properly.If you tie a knot with the loop, it won't come undone.Take the loop off the pencil and make sure it isn't too tight.
Step 3: You can make a small hook with a metal wire.
If you want to make a hook, you need to take a 2 in (5.1 cm) length of metal wire and curl one end into a J shape.If you want to change the weight of the pendulum, it is easy to attach and remove nuts from the hook.The pliers can be used to curl the wire.
Step 4: The end of the hook has a 4 inch nut on it.
The metallic nut is the weight for your pendulum.The hole in the center makes a nut ideal for sliding onto the hook, and you can easily add or remove nuts to experiment with different weights.If you slide the nut onto the hook, it will not fall when the pendulum swings.Don't close the hook around the nut.
Step 5: There is a piece of paper behind the hook.
If you mark where you release the pendulum with the paper, you can see how it swings.Place the paper behind the hook with the nut on it to make it look like a backdrop.If you can see the pencil markings on the paper, it's fine.
Step 6: Pull the hook with the nut on it.
Use your pencil to mark on the paper behind the pendulum where you will release it.If you allow the pendulum to go from the same place each time, you can repeat the experiment.For accurate results in your experiments, you need to have a consistent release point.
Step 7: Start a stopwatch by releasing the pendulum.
Count the number of times the pendulum swings back and forth for a minute after you release it.Each time, the pendulum will be released from the same spot on the paper.Don't push or swing the pendulum.You can calculate an average by writing down the number of oscillations.
Step 8: The average of the oscillations can be calculated.
Take the number of oscillations from each time you release the pendulum, add them all together, and divide by 5.The pendulum completes from that distance and weight.
Step 9: The mass makes a difference if a nut is added to the hook.
Bring the pendulum back to where you marked on the paper the first time by adding a second nut to the hook.When you release the pendulum, take a minute to count the number of oscillations.Then calculate your average by repeating the process 5 times.There is a difference in the number of oscillations and the average between the nuts on the hook.If more mass will affect the pendulum, add another nut and repeat the experiment.
Step 10: You can change the distance to see what happens.
If you want to repeat the experiment from the same distance, you have to make a mark on the paper behind the string so you can see it again.You can count the number of oscillations by releasing the pendulum.You have to repeat the process 5 times.You may be surprised to learn that the distance does not affect the swing rate.If you want to see how much of a difference the distance makes, try the experiment again from 5 inches.
Step 11: To see the effects, cut off 10 inches of the string.
Take the look off of the pencil and cut off 10 inches (25 cm) of string, tie another loop and put it back on.You need to mark on the paper where you will release the pendulum.To see how the length of the string affects the pendulum, repeat the experiment 5 times.To see the difference it makes on the average number of oscillations, cut off another 25 cm of string.Pendulums have been used to keep time because they help determine the speed and regularity of the swings.