How should I calculate the distance D with two different motions?

[simphys]

Homework Statement

An important piece of landing equipment must be thrown to
a ship, which is moving at 45.0 cm>s, before the ship can dock. This
equipment is thrown at 15.0 m>s at 60.0° above the horizontal from the
top of a tower at the edge of the water, 8.75 m above the ship’s deck
(Fig. P3.54). For this equipment to land at the front of the ship, at what
distance D from the dock should the ship be when the equipment is
thrown? Ignore air resistance

Relevant Equations

kinematic equations

My question is this:
So in my solution, to get D I *substracted* the displacement of the boat within the same time interfval of the projectile motion from the range of the projectile motion. whilst in the solutions it says that I need to *add* them together.
Question: Why do I need to add them as the boat is going in the opposition direction, and from my reasoning I would think that the distance D would become smaller this way.

 

[simphys]

edit: forgot the solution

 

[BvU]

So in my solution

I don't see no solution ?
Please post your work...

Anyway, if you deal with the signs properly, this shouldn't be a problem...

$\$

 

[simphys]

I don't see no solution ?
Please post your work...

Anyway, if you deal with the signs properly, this shouldn't be a problem...

$\$

I have ?

 

[simphys]

Oh gosh my apologies... wow I just find out at that it is says the distance D from the time when the equipment is thrown... mine was at the end of the thrown then..

My apologies for posting!

 

[BvU]

I have ?

Yes, after I posted

[edit] can hardly decipher it anyway ...

 

[simphys]

Yes, after I posted

[edit] can hardly decipher it anyway ...

Yeah my apologies :) I needed to quickly switch to the phone to post the pic afterwards. But for some reason it always pixelates my picture lol, they look crisp and clear when I look at it on the camera roll, strangeee

 

[BvU]

Miraculous camera if it can clarify those scribbles