Answer:
Vertical Height = 0.784 meter, Speed back at starting point = 10 m/s
Explanation:
Given Data:
V is the overall velocity vector,
and
are its initial vertical and horizontal components

To find:
Max Height
achieved
Calculation:
1) Using the
equation of motion, we know

2) In terms of gravity
height
and the vertical component of Velocity
.
3) As
as at maximum height the vertical component of velocity is zero maximum height achieved

putting values
4) 
5) As for the speed when it reaches back its starting point, it will have a speed similar to its launching speed, the reason being the absence of air friction (Air drag)
Look at your speedometer for say, a couple of seconds. Depends on whether or not you are moving on average at a constant speed (speedo won't change much) or whether you're in a polluting traffic jam/queue in which case the speedo will go up and down like a yo yo. to determine the speed, you'd probably need to plot the speed on the speedo against the times at which the speedo speeds were read from the speedo.
If you are talking about ocean waves crashing into each other, they would probably mostly cancel out with just a bit of motion left over. If you are talking about things like frequency and amplitude, overlapping waves would combine and amplify or suppress each other, depending on their direction, position, frequency and amplitude. If the two waves complement each other, they amplify; if they conflict with each other, they are suppressed.