Height of the two balls collision

[larryboi7]

Homework Statement

Ball A is dropped from the top of a building of height 'h' at the same instant that Ball B is thrown vertically upward from the ground. When the balls collide, they are moving in opposite directions, and the speed of A is twice the speed of B. At what height does the collision occur?

Homework Equations

x1=x0 + volt - 1/2gt^2

I've been having a hard time with this. I just can't get it.

 

[berkeman]

Homework Statement

Ball A is dropped from the top of a building of height 'h' at the same instant that Ball B is thrown vertically upward from the ground. When the balls collide, they are moving in opposite directions, and the speed of A is twice the speed of B. At what height does the collision occur?

Homework Equations

x1=x0 + volt - 1/2gt^2




I've been having a hard time with this. I just can't get it.

Usually you will use "y" for the vertical position variable (small point, but confusing otherwise).

Write an equation for the position of each ball as a function of time, and set them equal (that's where they collide in the y axis)... Please show us your work so that we can help you.