S
[tex]\begin{gathered} \frac{x}{sinx}=\frac{4}{100} \\ \\ x=3.11km \end{gathered}[/tex]
Speed v
[tex]\begin{gathered} Speed\text{ =}\frac{x}{30} \\ \\ Speed\text{ V=}\frac{3.111}{30} \\ \\ Speed\text{ V=}0.1037\text{ }kmper\text{ sec} \\ \end{gathered}[/tex]
Covert to km per hour
By multiplying by 60
The final answer
[tex]6.222km\text{ per hour}[/tex]
