Pendahuluan:

Apakah Anda siap untuk meresapi dunia dinamika fluida? Bersiaplah untuk terkesima saat kami memulai perjalanan eksplorasi yang akan membuat Anda meragukan sifat pergerakan itu sendiri. Dalam artikel hari ini, kami akan mengungkapkan hubungan menakjubkan antara berbagai cairan dan kecepatan gerakan bola di dalamnya. Bersiaplah untuk melihat sendiri bagaimana cairan dapat membentuk kesan kita tentang kecepatan dengan cara yang sebelumnya tidak pernah Anda bayangkan! Jadi, kencangkan sabuk pengaman Anda dan bergabunglah dengan kami dalam perjalanan ini melalui viskositas cairan, kepadatannya, dan gaya yang mengatur interaksinya.

Bagaimana berbagai cairan memengaruhi kecepatan gerakan bola di dalamnya?

Berbagai cairan memengaruhi kecepatan gerakan bola selama bola bergerak di dalam cairan tersebut.

- Eksperimen dilakukan dengan menggunakan tiga jenis cairan yang berbeda, yaitu gas, cair, dan padat.

- Sebuah bola kaca kecil dijatuhkan ke dalam setiap cairan, dan waktu yang diperlukan untuk bola mencapai dasar wadah dicatat.

Bagaimana suhu cairan memengaruhi kecepatan bola yang bergerak di dalamnya?

- Hipotesis tentang bagaimana suhu cairan memengaruhi kecepatan bola dapat diajukan.

- Desain eksperimen untuk memverifikasi hipotesis ini.

Tujuan: Memahami pengaruh berbagai cairan terhadap kecepatan gerakan dan pengaruh suhu cairan terhadap bola yang bergerak di dalamnya.

Langkah-langkah: Selembar kertas dibagi menjadi tiga bagian yang sama, dan sebuah bola kaca kecil dijatuhkan ke dalam cairan yang berbeda, kemudian waktu diukur.

Analisis: Bandingkan waktu di berbagai cairan, dan tarik kesimpulan tentang hubungan antara waktu dan kecairan.

Rancang eksperimen untuk memahami pengaruh suhu cairan terhadap kecepatan bola.

Gas:

Gas memperluas dan menyebar, serta dapat dimampatkan; karena itu memiliki kepadatan rendah dan terdiri dari partikel yang sangat kecil yang selalu bergerak.

Jika Anda tidur di tempat tidur udara yang dipompa, pasti Anda akan melihat perbedaan antara itu dan tidur di tanah, dan Anda pasti merasakan kenyamanan dan kehangatan ketika menggunakan kasur yang mendapatkan sifatnya dari partikel udara yang dikompres di dalamnya.

Teori Kinetik-Molekuler (The Kinetic-Molecular Theory):

Anda telah belajar sebelumnya bahwa struktur materi (jenis partikel penyusunnya) dan tata letaknya (aturan partikelnya) menentukan sifat kimianya, dan juga memengaruhi sifat fisiknya. Berdasarkan pada penampilan luar materi, Anda dapat membedakan antara emas, grafit, dan raksa, dan sebaliknya, materi yang berada dalam fase gas pada suhu kamar memiliki sifat fisik yang serupa, meskipun berbeda dalam strukturnya. Mengapa ada perbedaan perilaku gas? Dan mengapa sifat fisik gas berbeda dari sifat materi cair dan padat?

Pada awal abad kedelapan belas, ilmuwan mengetahui cara mengumpulkan gas melalui penggantian air, tetapi sekarang mereka dapat mengamati setiap gas, dan mengukur sifatnya secara terpisah. Pada tahun 1860, Boltzmann dan Maxwell masing-masing mengusulkan model untuk menjelaskan sifat-sifat gas. Model ini dikenal sebagai teori kinetik-molekuler karena semua gas yang diuji oleh Boltzmann dan Maxwell terdiri dari partikel; di mana benda yang bergerak memiliki energi yang disebut energi kinetik. Teori kinetik-molekuler menjelaskan perilaku materi dengan bergantung pada gerakan partikelnya. Model ini membuat beberapa asumsi tentang ukuran partikel gas, gerakan dan energi mereka.

Volume of Particles:

Gases consist of particles with very small volumes compared to the spaces between them, and they are also widely spaced, so the forces of attraction and repulsion between them are negligible. The movement of gas particles is continuous and random; they move in a straight line until they collide with other particles or the walls of the container they are in, and collisions between gas particles are elastic. In elastic collisions, kinetic energy is not lost but is transferred between colliding particles.

Particle Energy:

The movement of particles generates kinetic energy determined by two factors: the particle's mass and its velocity. The kinetic energy (KE) of a particle can be expressed by the following relationship:

\[ KE = \frac{1}{2} m v^2 \]

Where: \( KE \) is the kinetic energy, \( m \) is the particle's mass, and \( v \) is the particle's velocity. We find that particles in a sample of gas have the same mass but different velocities, leading to variations in their kinetic energy. Therefore, temperature is used as a measure of the average kinetic energy of the substance's particles.

Explaining the Behavior of Gases:

The kinetic molecular theory helps explain the behavior of gases. The continuous movement of particles, for example, allows a gas to expand to fill the entire container it occupies, as seen when inflating a balloon. Gas particles spread out and distribute to fill the container completely.

Low Density:

Remember, mass per unit volume, and the density of chlorine gas at a temperature of 200 equals \(10 \times 2.95 \, \text{g/mL}\), and the density of solid gold equals \(19.3 \, \text{g/mL}\). Thus, the density of gold exceeds that of chlorine by approximately 6500 times. This large difference in density is not only due to the difference in the mass of gold atoms and chlorine particles but also to the presence of a large void between gas particles. Therefore, the number of chlorine particles is less than the number of gold atoms in the same volume, as the kinetic molecular theory suggests.

Compression and Expansion:

If you compress a polystyrene pillow by applying pressure, its volume decreases. This happens because the distance between the particles is initially large, and when pressure is applied, the particles start coming closer together, reducing the volume. When pressure is released, due to the rapid and random motion of particles, they move away from each other, increasing the distances, and the substance returns to its original state.

Diffusion and Flow:

According to the kinetic molecular theory, and since the distance between gas particles is large, the forces of attraction between them are almost negligible. Hence, these particles easily spread out, and the place where the gas spreads is often occupied by another gas. The random movement of gas particles causes them to mix, resulting in the even distribution of mixed gases.

Diffusion describes the movement of substances intermingling. This term might be modern, but the process of diffusion is familiar to you. For example, you smell the aroma of food being cooked throughout your entire house due to the spread of gas particles from an area of high concentration (the kitchen) to an area of low concentration (the rest of the house).

Flow is related to diffusion, and it occurs when gas exits through a small hole. What happens, for instance, when there's a hole in a car tire or a balloon? Thomas Graham conducted an experiment in 1846 to measure the rate of flow of different gases at the same temperature. He designed his experiment so that the gases flowed into an area where there was no substance. He discovered an inverse relationship between the flow rate and the molar mass of the gas. Graham's law of effusion states that the rate of gas flow is inversely proportional to the square root of the molar mass.

Conclusion:

1. We explored how different liquids can affect the speed of a ball's movement within them. We also discussed the kinetic molecular theory and how it helps us understand the behavior of gases and explain their properties.

2. Liquids vary in their physical properties such as viscosity and density, and these properties affect the speed of movement of objects within them. The kinetic molecular theory helps us understand the behavior of gases and how they expand and flow, as well as the relationship between the speed of diffusion and the molar mass of the gas.

3. Studying fluid dynamics opens a window to an amazing world of interactions between liquids and moving objects within them. Whether dealing with light and rapidly spreading gases, flowing and expanding liquids, or solid bodies characterized by stability and reflections, these studies help us understand the physical behavior of substances.

4. With a deep understanding of molecular motion and how different factors such as mass and temperature affect the behavior of liquids and gases, we can apply this knowledge in a variety of fields, from chemistry and physics to everyday applications like .heating and air conditioning

Terapkan sendiri eksperimen tersebut melalui platform Vlaby untuk laboratorium sains virtual