SOLUTION: The height, h, of a ball on the moon t seconds after it is thrown upward with an initial velocity of 5meters per second is modeled by h= -0.8t squared + 5t. When will the ball land

Algebra ->  Radicals -> SOLUTION: The height, h, of a ball on the moon t seconds after it is thrown upward with an initial velocity of 5meters per second is modeled by h= -0.8t squared + 5t. When will the ball land      Log On


   

Question 605634: The height, h, of a ball on the moon t seconds after it is thrown upward with an initial velocity of 5meters per second is modeled by h= -0.8t squared + 5t. When will the ball land on the moon?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Note that +h+=+0+ at the instant the ball
is thrown upward, but also, +h+=+0+ when the ball
commes back to the surface, so:
+0+=+-.8t%5E2+%2B+5t+
+t%2A%28-.8t+%2B+5%29+=+0+
The solutions are +t+=+0+ ( when ball is thrown )
and also,
+-.8t+%2B+5+=+0+
+.8t+=+5+
+t+=+5%2F.8+
+t+=+6.25+
The ball lands 6.25 sec after it is thrown