1. The problem statement, all variables and given/known data ball dropped in air at 20m/s. why is v=20,v0=0 instead of v0=20,v=0 2. Relevant equations a=v-v0 / t s=x0+v0xt + at2/2 3. The attempt at a solution a=g=9.8m/s2 I know I can solve it with first finding time(I get that) a=v-v0/t making it into t=v-v0/g so 20/9.8=2.04s but now from what I understand 20m/s is v0 is it not? can someone explain is it or is it not initial velocity, and why we don't use s=v0xt+ gt2/2 but instead s=gt2/2 I know the answer is 20.4m, or maybe it's actually wrong?