SOLUTION: A ball is thrown from an initial height of 2 meters with an initial upward velocity of 25 m/s
. The ball's height
h (in meters) after t
seconds is given by the following.
h=2
Question 1120299: A ball is thrown from an initial height of 2 meters with an initial upward velocity of 25 m/s
. The ball's height
h (in meters) after t
seconds is given by the following.
h=2+25t-5t^2
find all values of t for which the ball's height is 7 meters
Round your answer(s) to the nearest hundredth.
You can put this solution on YOUR website! h=7
7=-5t^2+25t+2
-5t^2+257-5=0
or 5t^2-25t+5=0
or t^2-5t+1=0
t=(1/2)(5+/-sqrt (25-4)); sqrt (21)=4.58
t=9.58/2 or 4.79 seconds (coming down)
t=0.42/2 or 0.21 seconds (going up)
Check of sorts: max height is vertex which is at -b/2a or -25/-10 or 2.5 seconds, which is a height of -31.25+62.5+2 or 33.25 m.
