Step 1:

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The projectile is fired at an upward angle is $\"\"$ .

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The projectile is fired from the height is $\"\"$ .

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The speed of projectile is $\"\"$ . $\"\"$

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$\"\"$

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Find the speed of the projectile when it reaches the ground $\"\"$ .

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The vertical velocity of the projectile is $\"\"$ .

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Substitute $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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Apply formula: $\"\"$ .

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$\"\"$

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$\"\"$ .

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$\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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The total height of the cliff is $\"\"$ .

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$\"\"$ .

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The total energy of an isolated system remains constant irrespective of whatever internal changes may take place with energy disappearing in one form reappearing in another.

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Potential energy transferred=kinetic energy gained.

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .