Answer:
2.61 m separation
Step-by-step explanation:
x = xo + vo t + 1/2 at^2 x o and vo = 0 so this becomes
x = 1/2 at^2
Find t when x = 3
3 = 1/2 (9.81)(t^2)
t = .782 sec
then the SECOND ball is at
x = 1/2 a t^2 but t is reduce by 1/2 second drop rate
x = 1/2 (9.81)(.782 - .5)^2 = .39 m
3 - .39 m = 2.61 m