# The Travel Time of Floatable Litter of Different Densities Influenced by River Flow Velocity
## 3 Results and Discussion  
### Analysis of Floatable Litter Characteristics  
The objects selected are all floatable but are made up of different types of material. The FL physical characteristic parameters measured in this study are mass, volume, size, and density as shown in Table 2.  
From Table 2, the biggest mass value, m = 0.277 kg, is a wood board (FL15) while the smallest mass value, m = 0.001 kg, is that of a cigarette butt (FL12). Mass is the measure of the amount of matter in an object. Mass is proportional to density; thus, the mass of FL is considered to be among the main physical characteristics of FL that affect its migration in rivers. For volume, the biggest volume is that of the cardboard box (FL10) with V = 0.00303 m\({}^{3}\) while the smallest volume is V = 0.000006 m\({}^{3}\) for the cigarette butt (FL12). Relating the volume and size of FL, FL10 is the largest while FL12 is the smallest FL. Volume is the amount of space taken up by a three-dimensional object. In another word, the volume represents the size of an object. Thus, FL10 and FL12 have the largest and smallest volume, respectively. However, for cloth (FL9), the volume is low, V = 0.000090 m\({}^{3}\), even though it is large in two-dimensional size, 57.0 \(\times\) 46.2 cm. For the parcel bag (FL18) the volume is only V = 0.000045 m\({}^{3}\) while its size is 26.0 \(\times\) 23.0 cm. This shows that the volume of an FL is lower despite its two-dimensional size when it is thin. The volume of FL is measured as one of the important FL characteristics because the volume is inversely proportional to density. volume change directly influence the density value. The biggest FL in size is 10.8 \(\times\) 10.8 \(\times\) 26.0 cm, a cardboard box (FL10), while the smallest size is 3.5 \(\times\) 0.8 cm, that of the cigarette butt (FL12). According to [16; 17], the size factor does affect its migration behavior. However, in this study, the size factor is not considered in studying FL travel time but, rather, as additional information in identifying each FL. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**No.** & **Objects** & **FL Code** & **Mass (kg)** & **Volume (m\({}^{3}\))** & **Size (cm)** & **Density (kg/m\({}^{3}\))** \\ \hline
1 & 1.5 mineral bottle & FL1 & 0.03 & 0.0015 & 31.0 \(\times\) 0.8 & 18.96 \\
2 & 0.5 mineral bottle & FL2 & 0.02 & 0.0005 & 21.4 \(\times\) 6.1 & 30.94 \\
3 & Body wash bottle & FL3 & 0.11 & 0.001 & 30.4 \(\times\) 11.5 & 108.89 \\
4 & Plastic bag & FL4 & 0.03 & 0.00002 & 23.0 \(\times\) 28.0 & 92.4 \\
5 & Polystyrene food packaging & FL5 & 0.01 & 0.00118 & 19.5 \(\times\) 14.0 \(\times\) 6.5 & 4.76 \\
6 & Crisp packet & FL6 & 0.01 & 0.0001 & 17.5 \(\times\) 30.0 & 91.4 \\
7 & Aluminum can & FL7 & 0.02 & 0.00024 & 13.0 \(\times\) 4.6 & 81.88 \\
8 & Diapers & FL8 & 0.05 & 0.00005 & 12.0 \(\times\) 21.0 & 961.2 \\
9 & Cloth & FL9 & 0.1 & 0.00009 & 57.0 \(\times\) 46.2 & 1154.4 \\
10 & Cardboard box & FL10 & 0.07 & 0.00303 & 10.8 \(\times\) 10.8 \(\times\) 26.0 & 22.59 \\
11 & Polystyrene foam & FL11 & 0.03 & 0.00065 & 28.3 \(\times\) 9.2 \(\times\) 2.5 & 39.57 \\
12 & Cigarette butt & FL12 & 0 & \(6\times 10^{-6}\) & 3.5 \(\times\) 0.8 & 169.49 \\
13 & Polymer foam & FL13 & 0.02 & 0.00068 & 10.15 \(\times\) 29.4 \(\times\) 13.0 & 33.03 \\
14 & Magazine paper & FL14 & 0.16 & 0.00023 & 21.0 \(\times\) 29.7 \(\times\) 0.5 & 678.57 \\
15 & Wood board & FL15 & 0.28 & 0.00039 & 29.2 \(\times\) 57.5 \(\times\) 0.3 & 714.67 \\
16 & Glass bottle & FL16 & 0.17 & 0.0003 & 20.0 \(\times\) 7.5 & 579.5 \\
17 & Slipper & FL17 & 0.06 & 0.00023 & 26.0 \(\times\) 9.5 & 247.11 \\
18 & Parcel bag & FL18 & 0.01 & 4.5 \(\times\) 10\({}^{-5}\) & 26.0 \(\times\) 23.0 & 273.33 \\
19 & Sanitizer bottle & FL19 & 0.01 & 0.00005 & 9.5 \(\times\) 3.5 & 243.4 \\
20 & Face mask 3-ply & FL20 & 0 & 1.5 \(\times\) 10\({}^{-5}\) & 16.0 \(\times\) 8.0 & 173.33 \\ \hline \end{tabular}
\end{table} 
Table 2: Physical characteristic parameters of floatable litter. Next is FL density. The range of FL density is 4.76-1154 kg/m\({}^{3}\).