Case A: Ball dropped downwards
initial vel., v0=0m/s
accl, a=-g=-9.8m/s^2
displacement, S=(x-400) m
Then we have
S=v0*t+0.5a*t^2
x-400= -0.5*9.8*t^2Case B: Ball thrown upwards
initial vel., v0=50m/s
accl, a=-g=-9.8m/s^2
displacement, S=(x-400) m
Then we have
S=v0*t+0.5a*t^2
x-400= 50*t-0.5*9.8*t^2We have 2 eqns:
(xβ400)=β0.5β9.8βt2
(xβ400)=50βtβ0.5β9.8βt2
Solving, we get
t=0 & x=400
This is the initial state.... which means that they never meet during the flight...