A stone is allowed to fall from the top of a tower 300m height and at the same time another stone is projected vertically up from the ground with a velocity 30m/s .Find when the two stones meet?

Let ‘t’ be the time after which the two stones meet∴ For a vertically projected upwards body  u=30 m/sa=g=−9.8m/s2s=x t=t∴ From Equation  s=ut+12at2   x=30t−12gt2...........(i)For a freely falling bodyu=0a=g=9.8m/s2s=yt=t∴ From equation s=ut+12gt2 y=12gt2………..(2) Given that x+y=300⇒30t=300⇒t=10s