A student throws a set of keys vertically upward to her sorority sister, who is in a window 4.35 m above. The second student catches the keys 2.65 s later. (a) With what initial velocity were the keys thrown? (b) What was the velocity of the keys just before they were caught? =-g. (a) We know that when t = 2.65 s, Ay = (y - y) = 4.35 m; also ay So we have the following equation. Y - Y = V -2912 Solving the above equation for v Y - Y - 2a,t 11 Substitute the values that we know into this equation. 20 m/s)( 4.35 t - we have the following. m/s 2.65 S s)