SOLUTION: A ball is thrown from a height of 49 meters with an initial downward velocity of 2 m/s. The bald height “h” (in meters) after “t” seconds is given by the following. H=49-2

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A ball is thrown from a height of 49 meters with an initial downward velocity of 2 m/s. The bald height “h” (in meters) after “t” seconds is given by the following. H=49-2      Log On


   

Question 1145285: A ball is thrown from a height of 49 meters with an initial downward velocity of 2 m/s. The bald height “h” (in meters) after “t” seconds is given by the following.
H=49-2t-5t squared
How long after the ball is thrown does it hit the ground?
Round to nearest hundredth
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
When ball hits the ground, +h+=+0+
+-5t%5E2+-+2t+%2B+49+=+0+
+t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
+a+=+-5+
+b+=+-2+
+c+=+49+
+t+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%2A%28-5%29%2A49+%29%29%2F%282%2A%28-5%29%29+
+t+=+%28+2+%2B-+sqrt%28+4+%2B+980+%29%29%2F%28-10%29+
+t+=+%28+2+-+sqrt%28+984+%29%29+%2F+%28-10%29+
+t+=+%28+2+-+31.369+%29+%2F+%28-10%29+
+t+=+29.369+%2F+10+
+t+=+2.937+
The ball hits the ground in 2.94 sec
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check the math & get a 2nd opinion if needed