The projectile (ball) reaches an instantaneous vertical speed (Vy) of zero at maximum height.
so, V(max height) = ¬Г(Vx)^2+(Vy)^2
in this case V(max height) = Vx, where Vy=0
The maximum height, Yf, can be solved using Vfy^2=Viy^2 + 2gy. At maximum height Vfy=0.
HCl + NaOH -> H2O + NaCl
CaCO3 + KI -> K2CO2 + CaI2
AlF3 + Mg(NO3)2 -> Al(NO3)3 + MgF2
Via the half-life equation:

Where the time elapse is 11,460 year and the half-life is 5,730 years.

Therefore after 11,460 years the amount of carbon-14 is one fourth (1/4) of the original amount.