Projectile Motion Ball off Cliff Help

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SUMMARY

The discussion focuses on solving a projectile motion problem involving a golf ball hit from a cliff. The ball's mass is 38 g, the cliff height is 46 m, and it takes 7.0 seconds to reach the ocean, landing 154 m from the base of the cliff. The user initially calculates the horizontal velocity as 22 m/s and attempts to find the vertical component of the initial velocity using the kinematic equations. However, the user fails to incorporate the cliff height correctly in their calculations, leading to discrepancies with the expected answer.

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I missed a few days of class and have a quiz tomorrow so I'm not entirely sure where to start with this. The question is:

A golfer hits a ball (m = 38 g) from a cliff top (h = 46 m) and times how long it takes to splash in the ocean (t = 7.0 s). The ball hits the water at a distance (x = 154 m) from the vertical cliff bottom. Find the ball's initial velocity and the angle of launch.

I have y = 46 m, x = 154 m, t = 7.0 s

I assume I have to use the two-dimensional kinematic equations, but I just can't seem to get anywhere towards finding the initial velocity.

My first thought was

x = v_0x * t

v_0x = 154 / 7 = 22 m/s

Then take

y = (v_0y)t+1/2 gt^2 = 7(v_0y) - 240.34

v_0y = 40.905

And then square both of those and take the square root. But the answer I get doesn't agree with the instructors, so I'm lost.
 
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You did not use the cliff height in the second equation.
 

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