We are talking about periodic movements, that is, movements that repeat themselves over a certain period of time. For example, the same pendulum.

Before starting to act, yellow boxes with important sentences, such as you often come across in textbooks, would show. Here you don't have to memorize them. But if we want to talk about something matter-of-factly, the first thing we should do is agree on what these words mean, what we use. Eksole, we usually feel pretty confident talking about cars, for example. Because we've seen cars and know what we generally mean by that word. And, by the way, even though we haven't learned the definition of the word "car" anywhere, we could probably come up with one ourselves. It should be the same with physics concepts - if you know what it is, you can come up with a definition yourself.

You will also find a simple formula here - how the frequency of a periodic oscillation is expressed according to its oscillation period. Also, two review questions that you might want to answer.

So:

Periodic motion

Recall or find out which motions are periodic and how periodic motions are characterized.

Mathematical pendulum in simulation

Mathematical pendulum in simulation

So much for the theory. Next, we will be practical and start studying one such pendulum. The first thing you need to do is assemble one pendulum base according to the video, then we will hang the pendulum on it. Next, you should measure the oscillation period of this pendulum. Once you understand what this oscillation period is, then it should be easy.

The result of the measurement should be written in the corresponding field on the worksheet. You should choose a pendulum length of 30 cm.

The period of oscillation of the pendulum

We assemble a tripod and hang a pendulum made of straw and a rubber stopper on it and measure its period of oscillation.

I do these tests like this:

VIDEO

We tried to make all pendulums of one length. Measured oscillation periods, as we saw, slightly different. But should it be the case that if we measure all our pendulums to the same length very precisely, then the oscillation periods will also be the same?

Also considering that not all of us have pendulums with one mass.

In other words, what does and does not depend on the period of oscillation of a pendulum?

Let's try it.

If we want to study something like this, we should do several experiments where we change one or another property of the pendulum, after which we also measure the period of oscillation. And then draw conclusions. When doing this first mini-research, we don't measure, we compare - we put another one next to the already existing pendulum. And let's try to answer the questions on the next slide.

I do these tests like this:

VIDEO

Now for the ugly slide where we do math. Although some of you may not like math, it can be really useful from time to time. And physics cannot do without mathematics.

We will get acquainted with mathematics through the pendulum formula. The formula also has a pendulum defined for which this formula is valid.

One property of the pendulum goes into the formula - its length. The period of oscillation of the pendulum can be calculated through the formula. The measured and calculated oscillation period should be the same?