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## Homework Statement

A ball is thrown off of a 15m cliff at an angle of 30 degrees above the horizontal and strike the ground 10.4 seconds later. Determine the initial velocity of the ball, the maximum height of the ball, and impact (final) velocity of the ball.

## Homework Equations

vo=vf+at

y=.5at+vot

x=vot

## The Attempt at a Solution

I'm really out of my depth on this problem. I really just have no clue where to begin, since I'm used to being given the initial velocity of the ball. I had an idea to try to divide up the time of the problem into two sectors, where the ball is in its parabolic motion in one section and the other where it comes back to the same level that it was launched at and continues to the ground. the time would be √2h/g correct? But can I use this even though there's a y component to the velocity? Is any of this even correct? How do I do this problem?

Or can I just say y=.5gt^2+vot

-15=.5(-10)(10.4)^2+vo(10.4)?

Vo=53.44?

Also isn't this just the vertical component of Vo? So shouldn't the full Vo be

Voy=VoSin30

53.44=VoSin30

Vo=106.88?

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