Calculating Building Height: Quick Kinematics Question

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A stone dropped from a building travels 1/5 of the building's height in the last second before hitting the ground. To find the building's total height, one can use kinematic equations, focusing on the distance fallen as a function of time. The problem can be solved with a single equation, as the unknowns will cancel out. The discussions highlight different methods to approach the calculation, emphasizing the simplicity of the problem despite initial confusion. Ultimately, the key is to apply basic kinematics to derive the building's height.
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A stone is dropped from the top of a building. Within the second before it hits the ground, it travels 1/5 of the building's height. Calculate the total height of the building.

Been trying to formulate simultaneous equations but there just doesn't seem to be enough information and too many unknowns >< Help appreciated!
 
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What is the speed of the stone just before it hits the ground? You only need one equation.
 
Show what you've done so far. How would you write the distance fallen as a function of time?
 
You don't need more info either as the unknowns will eventually cancel out. There are actually a couple of different ways to solve this.
 
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