please solve these problems step by step , will be really appreciated.

16- A particle leaves the oligin with inial velocity 1v1 n=9.i\"+1?j\"mfsvao=9.i*+1 ?j\"m.ls, undergoing constant acceleration ail =D.9l]i"'+.2 1j"'n:l_af sea+=.lli\"+tl.21j\"ml52.When does the particle cross the yaxis? 1ll'nl'hat's its ycoordinate at the time? How fast is it moving? In what direction is it moving? IT You throw a baseball at a 45mm angle to the horizontal, aiming at a friend who's sitting in a tree a distance hh above level ground. At the instant you throw your ball, your friend drops another ball. The two balls will collide, no matter what your balls initial speed, provided it's greater than some minimum value. Find an expression for that minimum speed. 18 In a chase scene, a movie stuntman runs horizontally off the flat roof of one building and lands on another roof 2.0 mm lower. If the gap between the buildings is 4.3 mm wide, how fast must he mn to cross the gap? 19 A soccer player can kick the ball 33 mm on level ground, with its initial velocity at 42 -n to the horizontal. At the same initial speed and angle to the horizontal, what horizontal distance can the player kick the ball on a 18 o0 upward slope?I 21!} A river leaves a 3mm board on a trajectory that takes her 2.5 mm above the board and then into the water 2.? mm horizontally from the end of the board. At what speed did she leave the board? At what angle did she leave the board