I am having some serious difficulety determining (b) the speed upon impact

In Fig. 4-36, a stone is projected at a cliff of heighthwith an initial speed of 48.0 m/s directed at an angle θ0 = 50.0° above the horizontal. The stone strikes atA, 5.21 s after launching. Find (a) the heighthof the cliff, (b) the speed of the stone just before impact atA, and (c) the maximum heightHreached above the ground.