Help regarding dynamics problem (see attachment):

Question

aero · Answer

attachment

aero · Answer

Determine the distance d to the farthest point B on the roof that the water can reach

agent0smith · Answer

Okay so basically the max distance... hmm pretty tricky. I don't know if i have time tonight (or even the patience to do this) but maybe tomorrow

shamim · Answer

Alpha=?

shamim · Answer

If alpha is given then i can solve ur problem

agent0smith · Answer

I don't think alpha needs to be given. Since the speed is given, and we know it has to pass right over the edge building, I think there is a particular trajectory,  since it has to pass through exactly the point at the edge of the building... and it can only pass through that point at two particular angles.

agent0smith · Answer

I could solve for the two angles... but i don't want to. But you can use the components of the velocity and the known x and y components, since they both have equal time values, so you can solve the equations for alpha: $$\large x = v \cos \alpha *t$$and $$\large y = y_o +v \sin \alpha *t +0.5at^2$$

aero · Answer

@Shamim α is not given. All the information needed is already given.

@agent0smith How would I be able to solve this given that both α and t are unknowns?

agent0smith · Answer

Because you can solve the first equation i gave for t, and plug it into the 2nd equation. The x and y values are the values at the left corner of the building. 

Then you can solve that 2nd equation for alpha.