SOLUTION: please i need urgent help here. pleaseeeeeeeeeeee The height of an object propelled upward from a height of 128 feet at an initial velocity of 112 feet per second is given by the

Algebra ->  Functions -> SOLUTION: please i need urgent help here. pleaseeeeeeeeeeee The height of an object propelled upward from a height of 128 feet at an initial velocity of 112 feet per second is given by the       Log On


   

Question 136113: please i need urgent help here. pleaseeeeeeeeeeee
The height of an object propelled upward from a height of 128 feet at an initial velocity of 112 feet per second is given by the equation h = -16t2 + 112t + 128. After how many seconds does the object hit the ground?

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Given: h+=+-16t%5E2+%2B+112t+%2B+128
When does it hit the ground? Means, when does h = 0
0+=+-16t%5E2+%2B+112t+%2B+128
0+=+-t%5E2+%2B+7t+%2B+8
+0+=+t%5E2+-7t+-8
+0+=+%28t-8%29%28t%2B1%29
t = 8, -1
Since t cann hit the ground a second before you throw it, the only reasonable answer is 8 seconds.
Check your answer by using 8 for t and finding h