The child is walking east, and the ship is moving north. The relative motion of the child to the water is found using vector addition. This means that the speed of the child to the water is

`v=sqrt{3^2+30^2}`

`=sqrt{9+900}`

`approx 30.15` km/h

The angle of direction is found using trigonometry, where 0 radians is given as north and east is `pi/2` radians. This means that the angle is:

`theta=tan^{-1}(30/3)=tan^{-1}10 approx 1.471`

But this is the angle north of east, and we want the angle east of north, so subtract it from `pi/2` to get:

`alpha=pi/2-theta=0.0997`

**The speed of the child relative to the water is 30.15 km/h and the angle of direction is 0.0997 radians.**

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