Collision of two Balls

sam.

1. The problem statement, all variables and given/known data

Ball 1 (B1) and Ball 2 (B2) are located at (x,y)=(0,0) and (x,y)=(d,h).
At t=0, B1 is sent towards the initial location of B2 with a speed vi. At the same
instant that B1 is launched, B2 falls towards the ground with zero initial velocity.
Assume there is no air resistance.

A diagram is attached below.

1. When and where do B1 and B2 collide?
2. If the initial speed of B1 is larger than vi, does a collision occur?
3. If B1 is directed towards a point slightly above the initial location of B2, can a
collision occur?
4. If B2 has an initial speed Vi in the negative y-direction, can B1 collide with B2?

2. Relevant equations

1. v_f = v_i + a[tex]\Delta[/tex]t
2. s_f = s_i +v[tex]\Delta[/tex]t +1/2a[tex]\Delta[/tex]t^2
3. v_f^2 = v_i^2 +2a[tex]\Delta[/tex]s
4. s_f = s_i + v[tex]\Delta[/tex]t

3. The attempt at a solution

Okay, I am really, really confused about this problem, but I tried #1.
I solved for the distance that Ball 1 travels using equation 4 and got:
s(ball 1) = cos[tex]\theta[/tex]v_it_1
Then for Ball 2 I used equation 2:
S(BALL 2) = h + 4.9t_1^2
Then I made both these equal each other:
h + 4.9t_1^2 - cos[tex]\theta[/tex]v_it_1 = 0
Now I know I can solve for time using quadratic formula but I'm not sure how to find where the balls meet. Also I am completely lost on how to solve for the rest of the questions. Please, someone help me out!! Any help is appreciated!

Attached Images

Physics pic.bmp (151.0 KB, 18 views)

physics2004

you can't use equation four because it is not constant velocity, (gravity has a role) therefore you'd have to use equation two twice for B1 and B2 then have the two equal because that will give you time of collision (it won't be a quadratic) then use T to get distance. Btw you used Cos(theta) when its Sin because its vertical component. and you know the x distance is d because thats where B2 is dropped so use vertical distance of B1 and d to find co-ordinate of the collision. i did it just now everything worked out fine.