Answer
\begin{aligned}
&2.2 m / s\\
&4.4 m / s\\
&0.021 \mathrm{m} / \mathrm{s}^{2}
\end{aligned}
Work Step by Step
\begin{aligned}
&\text { From Equation } 2.2\\
\frac{L}{t}=&v_{A}\\
&=>\frac{460 m}{210 s}=v_{A}\\
&=>2.2 \mathrm{m} / \mathrm{s}=v_{A}\\
&2 \bar{v}_{B}=v_{B}\\
&=>2 v_{A}=v_{B}\\
&=>2(2.2 \mathrm{m} / \mathrm{s})=v_{B}\\
&=>4.4 \mathrm{m} / \mathrm{s}=v_{B}\\
&\text { From equation } 2.4\left(v_{B}=v_{B 0}+a_{B} t\right)\\
&a_{B}=\frac{v_{B}-v_{B 0}}{t}\\
&=>\frac{4.4 \mathrm{m} / \mathrm{s}-0 \mathrm{m} / \mathrm{s}}{210 \mathrm{s}}=a_{B}\\
&=>0.021 \mathrm{m} / \mathrm{s}^{2}=a_{B}\\
\end{aligned}
