Viskositas

(A)   besar gaya gesekan saat kecepatannya 5 m/s

\begin{equation*}
\begin{split}
F_s & = 6 \pi \:.\: \eta \:.\: r \:.\: v \\\\
F_s & = 6 \:.\: 3,14 \:.\: 5 \:.\: 0.1 \:.\: 5 \\\\
F_s & = 47,1 \text{ N}
\end{split}
\end{equation*}

(B)   besar kecepatan terminal

\begin{equation*}
\begin{split}
\Sigma F & = m \:.\: a \\\\
w - F_s & = m \:.\: a \\\\
m \:.\: g - 6 \pi \:.\: \eta \:.\: r \:.\: v & = 0 \\\\
6 \pi \:.\: \eta \:.\: r \:.\: v & = m \:.\: g \\\\
6 \pi \:.\: \eta \:.\: r \:.\: v & = \rho_b \:.\: V \:.\: g \\\\
6 \pi \:.\: \eta \:.\: r \:.\: v & = \rho_b \:.\: \frac 43 \pi \:.\: r^3 \:.\: g \\\\
v & = \frac {2 \:.\: \rho_b \:.\: r^2 \:.\: g}{9 \:.\: \eta} \\\\
v & = \frac {2 \:.\: 9.000 \:.\: (0,1)^2 \:.\: 10}{9 \:.\: 5} \\\\
v & = 40 \text{ m/s}
\end{split}
\end{equation*}