Finding initial velocity given max height and distance only

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SUMMARY

The discussion focuses on calculating the initial velocity of a golf ball that reaches a maximum height of 20 meters and lands 130 meters away. The angle of projection was determined to be 31.6 degrees. The user attempted to use the equation vi cos(31.6) = 130 / (1/2)((-vi sin(31.6))/-9.81) but struggled to isolate the initial velocity (vi). The conversation emphasizes the need for a clearer method to solve for initial velocity in projectile motion problems.

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Homework Statement



A golfer hits a ball, giving it a maximum height of 20 m. If the ball lands 130 m away at the level from which he hit it, what was its initial velocity? (Neglect air resistance)

Homework Equations





The Attempt at a Solution



I found the angle to be 31.6, so I tried vi cos 31.6 = 130 /(1/2)((-vi sin 31.6)/-9.81), but I'm not seeing how to solve for initial velocity. There has to be an easier way to do this, and I'm convinced I'm making it more complicated than it really is!

Any help would be appreciated!
 
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How do you get the angle to be 31.6°?
 

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