As you look out of your apartment window, you see water balloons falling past. You measure that the balloons are visible (going past the window)for a time t, and the vertical length of your window is L_w. assume that the water balloons were dropped (rather than thrown downward). Determine then height h (above the top edge of your window) from which it was dropped. This will be an algebraic expression in terms of t, L_w, and g. my approach: known's: a_y= -g Vi_y= 0 Vf_h=Vi _(L_w) Picture I made to help with solution http://yfrog.com/5hbaloonfallingj My use of kinematics Vf _h= -g*t which also means Vi_(L_w) = -g*t Yf_h = Yi_(L_w) L_w = Yi_(L_w) - g*t*t - (1/2)g*t^2 ------> Yi_(L_w) = L_w +(1/2)g*t^2 Yf_h = Yi_h - (1/2)g*t^2 ----> L_w +(1/2)g*t^2 = Yi_h -(1/2)g*t^2 --(solve for Yi_h)--> Yi_h = g*t^2 + L_w Answer: [Yi_h = g*t^2 + L_w] is the algebraic expression to find height above the top of window edge. This is what I came up with and wondering if this is the correct answer for this problem?