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Question
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
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Solution
Initial velocity, u = 0 m s-1
Final velocity, v =?
Height of the tower, h = 19.6 m
Acceleration due to gravity, g = 9.8 m s-2
Using the equation, v2 - u2 = 2gs = 2gh
v2 - 0 = 2 × 9.8 m s-2 × 19.6 m
v2 = 19.6 m s-2 × 19.6 m
v2 = (19.6)2 m2 s-2
or v = 19.6 m s-1
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