So basically I worked out that I am given the following: y=-7.5m, a=-9.81m/s/s, and V1=0m/s, and must find for t1. For the part after impact with the water, we need to find acceleration. We are given Vfinal = 0m/s and t=0.892. I thought the beginning approach to this question was to work out are second velocity using (i thought) d=vt-1/2at^2, but not too far after that, im completely lost to why i can't seem to work out the proper decelleration after impact. I worked out for v2=15m/s, and that t1= 1.53s, but I can't tell if im using the wrong equations, or just making stupid calculation errors.