SOLUTION: A baseball is thrown upward with a speed of 128 feet per second. Let h=128-16x^2 model the height of the ball, h, after x seconds. When will the ball land on the ground?

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Question 701779: A baseball is thrown upward with a speed of 128 feet per second. Let h=128-16x^2 model the height of the ball, h, after x seconds. When will the ball land on the ground?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
They are asking when +h+=+0+ for the 2nd time.
+h+=+128x+-+16x%5E2+
+0+=+-16x%5E2+%2B+128x+
+0+=+x%2A%28+-16x+%2B+128+%29+
+-16x+%2B+128+=+0+
+16x+=+128+
+x+=+8+
The ball hits the ground in 8 seconds