IB Physics HL IA (23/24): How does the drag coefficient vary as the dimensions of woodblocks change?

Research Question

How does the drag coefficient vary as the dimensions of woodblocks change?

I. Introduction

From when I first learned about free fall, I was able to understand that the gravitational acceleration is the same for any objects that are in gravitational field in the Earth. However, it was hard to understand from my common sense, because as I knew, papers or ants fell much slower than other massive objects such as elephants or giraffes. Then, I came to know that the drag force, or air resistance, is one of the key factors that determines the acceleration of a falling object.

It was not very surprising to know that cross-sectional area affects the drag force, but it was quite interesting that the shape of the object can also affect the drag force. The numeric value that represents the magnitude of the impact of the shape on the drag force, is called as the ‘drag coefficient’. However, I could not find whether the dimensions of the shape (especially the dimensions of rectangular object) affect the drag coefficient. Hence, in this research, to satisfy my self-interest, I will investigate the impact of the dimensions of woodblocks on the drag coefficient. “How does the drag coefficient vary as the dimensions of woodblocks change?”