A stone is dropped from a height of 49m and simultaneously another stone is thrown upwards from the ground with a speed of 40m/s.when and where do the two stones meet?

Answer 1

falling stone: hf=49-4.9t^2
rising stone: hf=0+40t-4.9t^2
set the equations equal (hf=hf), and solve for time t, then put that t into either of the original equations and solve for hf.