Planetary Motion
Have you ever wondered how planets, asteroids, and stars always move in circular paths, especially near the orbit of a star or planet? Do orbit, mass, or both have something to do with this phenomenon, or perhaps is there a connection between the planets and the cosmos that we can’t physically see? Do celestial bodies in the universe randomly move in this predicted way, or is there something more that we can’t see? On this page, we would like to answer all these questions by exploring the idea of planetary motion and showing how physics can be applied to the outside world and consequently, the universe. The topic of planetary motion delves into how objects in space seemingly move without the aid of applied forces, rather, it is caused by one that is innately brought upon by masses of large or small objects. Through quantities, formulas, problems, applications, and citations, we will dig deeper into its full explanation to understand its meaning. Additionally, exploring how this concept helps with the development of human technology for interstellar travel will also be discussed, as well as the potential implications for our understanding of the cosmos. Let's embark on this journey of celestial exploration and scientific inquiry together, starting here!
Periodic Motion
Have you ever wondered how a guitar works and produces a mesmerizing sound wherein when you pluck the strings it will automatically move back and forth and you can also feel that the guitar vibrates. Well, to explain that, the guitar strings undergo periodic motion when they vibrate. When a guitar string is plucked, it is displaced from its equilibrium position and then released. The tension in the string, along with its elasticity, causes it to return to its original position. However, due to its inertia, it overshoots and gets displaced in the opposite direction. This back-and-forth motion continues, resulting in the string vibrating at its natural frequency. The vibrating guitar string produces sound waves, which we perceive as sound when they reach our ears. The pitch or frequency of the sound depends on the frequency of the string's vibration, which is determined by factors such as the tension in the string, its length, and its mass per unit length. By pressing down on different frets of the guitar neck, the effective length of the vibrating portion of the string can be changed, altering its frequency and producing different musical notes. Periodic motion is applied in different ways but it is the movement thoroughly repeated in equal intervals of time (The Editors of Encyclopaedia Britannica, 1998).
Mechanical Waves and Sounds
A wave is a disturbance that travels or propagates from the place where it was created. Waves transfer energy from one place to another, but they do not necessarily transfer any mass. Light, sound, and waves in the ocean are common examples of waves. Sound and water waves are mechanical waves; meaning, they require a medium to travel through. The medium may be a solid, a liquid, or a gas, and the speed of the wave depends on the material properties of the medium through which it is traveling. However, light is not a mechanical wave; it can travel through a vacuum such as the empty parts of outer space.
A familiar wave that you can easily imagine is the water wave. For water waves, the disturbance is in the surface of the water, an example of which is the disturbance created by a rock thrown into a pond or by a swimmer splashing the water surface repeatedly. For sound waves, the disturbance is caused by a change in air pressure, an example of which is when the oscillating cone inside a speaker creates a disturbance.
Light as an Electromagnetic Wave
Waves refer to disturbances that travel outwards or propagate from a source. Waves are a way to transfer energy thus will always involve energy, but it is important to note that waves do not necessarily transfer mass. Examples of waves that have no transfer of mass involved are light and sound.
Now onto the main focus, MECHANICAL WAVES. Mechanical waves are waves that require a medium for them to be able to travel; mediums can be solid liquid, or gas and the speed of the wave will depend on the physical properties of the medium. Examples of mechanical waves are sound and water.
To make waves easier to understand and visualize, imagine a water wave where the disturbance occurs on the water's surface.
There are many things that can cause a disturbance. For water, something as simple as a rock being thrown into a pond can cause a disturbance. For soundwaves, one cause will be a change in the air pressure where it is traveling.
