Calculate the time to reach a height of 49 m:
S = V0 t - 1/2 g t^2
S = 34.3 t - 1/2 * 9.8 * t^2
4.9 t^2 - 34.3 t + 49 = 0
I get t = 2 and t = 5 as solutions of the quadratic.
We know that it takes v / a = 34.3 / 9.8 = 3.5 sec to reach maximum height.
So we have:
2 sec to reach 49 m
3.5 sec to reach max height
1.5 sec from 49 m to max height
1.5 sec from max height back down to 49 m
2 sec to fall from 49 m to ground
2 sec + 1.5 sec + 1.5 sec = 5 sec to go from ground to max height and back down to 49 m
