1. The problem statement, all variables and given/known data A ball was projected at an angle A to the horizontal. One second later another ball was projected from the same point at an angle B to the horizontal. One second after the second ball was released, the two balls collided. Find the speed of projection for the two balls. 2. Relevant equations s = ut + 1/2 at2 3. The attempt at a solution In x-direction: sA = ua cosA t sB = ub cosB (t-1) In y-direction: sA = ua sinA t -1/2 gt2 sB = ub sinB (t-1) -1/2 g(t-1)2 When they collide the distances they travelled in the x and y directions are equal to each other at t=2. I tried to solve for ua and ub but got stuck.