Question

A projectile is launched from ground level at a velocity of 100m/sec at 30 degree angle?
I am trying to find the max height achieved.
I have already found the following

time=5.1s
change in y = 130 m
change in x = 510 m
Final velocity of y = 50 m/sec
final velocity = 110 m/s

Answer 1

You've already calculated the change in y, 130 m. This is the maximum height achieved, assuming the projectile begins and ends its trip from ground level.