Answer:
It changes at a rate of 4/3 meter per second
Explanation:
In the given figure below we have
[tex]\Delta OBD\simeq \Delta ABC\\\\\therefore \frac{5}{X+Y}=\frac{2}{Y}\\\\[/tex]
Solving for Y given [tex]X=2m/s[/tex] we get
[tex]\frac{5}{2+Y}=\frac{2}{Y}\\\\5Y=4+2Y\\\\Y=\frac{4}{3}m/s[/tex]