M22 물리 Physics EE (Grade A)

IB Physics Extended Essay

1. Introduction

Fluid mechanics, a branch of engineering that describes the behavior of fluid (gas and liquid), is one of the most important and interesting branches of engineering and well known for its complexity due to the randomness of fluid’s motion; “it is a branch of classical physics with applications of great importance in hydraulic and aeronautical engineering, chemical engineering, meteorology, and zoology” (Faber, 2019). Adding on, the flower of fluid mechanics, Navier-Stokes Equations, a partial differential equation that describes the motion or flow of the fluid, is one of the Millennium Problems as it has not yet been proven whether the equation always has a smooth solution in 3 dimensions. This is one of the main reasons that motivated me to select physics as my extended essay subject and investigate fluid dynamics in particular.
The interest in viscosity of a fluid has existed in my mind since I was young. Whenever my throat sored, I loved mixing honey with hot milk to make a “honey milk,” as my grandmother called it. When I poured honey into the hot milk, I always got annoyed by how slow the honey flowed into the hot milk from the plastic bottle. This experience allowed me to question myself, “why does honey take so much more time to flow than water?” I have forgotten about this question until I watched a video about viscosity on YouTube about a year ago. The video reminded me of the question that I came up with when I was very young, which motivated me to conduct research regarding viscosity of a fluid in this extended essay. After doing research on viscosity by watching various videos regarding viscosity, I could find out that more force is required to move more viscous fluid. I then eventually became curious about the correlation between fluid’s viscosity and the wave’s characteristics as I really enjoyed learning topic 4 and topic 9 of IB physics, which is all about waves. The interest in wave and viscosity allowed me to combine two different topics to develop a unique and intriguing research question. Therefore, in this extended essay, I will be focusing on answering the following question: How do changes in viscosity of fluid affect the speed and amplitude of surface waves that are generated by an impact of spherical object?