SOLUTION: If the rock is dropped from the second floo which has a height of 128ft, a) how long will it take to fall half the distance to the ground? b) how long will it take to fall to the g

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Question 1187331: If the rock is dropped from the second floo which has a height of 128ft, a) how long will it take to fall half the distance to the ground? b) how long will it take to fall to the ground?
Answer by Alan3354(69443) About Me  (Show Source):
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If the rock is dropped from the second floo which has a height of 128ft, a) how long will it take to fall half the distance to the ground? b) how long will it take to fall to the ground?
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128 feet is unusual for 2 stories.
Using 32 ft/sec/sec for gravity:
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a) how long will it take to fall half the distance to the ground?
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s = at^2/2 = 64 ft
16t^2 = 64
t = 2 seconds
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b) how long will it take to fall to the ground?
s = at^2/2 = 128 ft
16t^2 = 128
t^2 = 8
t+=+2sqrt%282%29 seconds