$\"\"$

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Initial position of the ball is $\"\"$ .

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Initial velocity of the ball is $\"\"$

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The position function $\"\"$

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Where $\"\"$ is the initial velocity of the ball

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$\"\"$ is the initial position of the ball

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Position function:

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$\"\"$

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$\"\"$

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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Sum and difference rule: $\"\"$ .

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$\"\"$

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Constant multiple rule and the power rule : $\"\"$ .

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$\"\"$

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$\"\"$

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Find the velocity after $\"\"$ .

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Substitute $\"\"$ in velocity function.

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$\"\"$

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The velocity of the ball after $\"\"$ is $\"\"$ .

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$\"\"$

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Find the velocity after falling $\"\"$ .

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Substitute $\"\"$ in position function.

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$\"\"$

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$\"\"$

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$\"\"$

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Time cannot be negative.

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Therefore, time at which position is $\"\"$ is at $\"\"$ sec.

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Velocity of the ball $\"\"$ at $\"\"$ .

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$\"\"$

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$\"\"$

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The velocity of the ball after $\"\"$ is $\"\"$ .

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The velocity of the ball after falling $\"\"$ is $\"\"$ .