Need Physics Help

[FFIX Choco Boy]

Ok, not sure if this thread would go here, the help forum, or idk where else, but here goes.

I was working on my Physics homework when I came to the last show my work problem, and I'm not sure where to go with it. The problem goes:

A ball is thrown from the top of a building toward a tall building 50 m away. The initial velocity of the ball is 20 m/s at 40 degrees above the horizontal.
a) How far above or below its original level will the ball strike the opposite wall. Declare if the ball will strike above or below the original level.
b) Calculate the angle of impact between the path of the ball and the wall.

I already have the a stuff, need the b answer, here's what I have so far.

Total time: 3.263518223 s

Y - direction
Delta Y: -10.2327929 m
Acceleration: -9.8 m/s/s (Duh)
Initial Velocity: 20 m/s X sin(40)

X - direction
Delta X: 50 m
Acceleration: 0
Initial velocity: 20 m/s X cos(40)

This is all assuming that the Earth is not spinning, is not curved, and neglecting air resistance.

I think what I need next is the Final Velocity for the Y - direction, which I can figure, but I don't know where to go from there.

[krissy]

you have initial velocity in the y
and you have the acceleration
and you have the total time

vf = vi + at

then you find the final velocity in the x

and you put the vectors together to make the new direction, which you can use to get the angle

[Raistlin]

I clicked on this thread because I read it as "need psychics help," so the reality turned out to be disappointingly boring.

[theundeadhero]

I'll move this to the help forum where you might have better luck :)

[FFIX Choco Boy]

Alright I got it, I figured the Final Velocity of Y at -19.12672639 m/s then did the arc tan of that and Vfx, and the answer checks out: -38.69542295. Thanks for the help Krissy.

Edit: What ever happened to the old homework forum that was on here?

[Raistlin]

I think we've had at least two incarnations of that forum, but the latest one was also removed due to lack of activity.

[theundeadhero]

Yep.