$[15]$ A guided missile $A$ is launched from point $O$ and pursues the hostile aircraft $B.$ The guidance system $2500m\frac{i}{h}r$ and the aircraft has a horizontal northerly velocity $u=800m\frac{i}{h}r.$ Determine the rate at which the distance $r$ between the aircraft and the missile decreasing for this position if the coordinates of A are $R=30mi,=60$ and $=12.$

$2$

ME$206$: Statics and Dynamics

K$.$ R$.$ Jayaprakash

Mechanical Engineering, IITGN

Figure $5$