SOLUTION: Question 825655: -This winter, Mr.walker was out playing in the snow with the Walker-lers. The snow was great packing snow for snowballs, so they gathered up some neighbors and sta

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Question 825655: -This winter, Mr.walker was out playing in the snow with the Walker-lers. The snow was great packing snow for snowballs, so they gathered up some neighbors and sta      Log On


   

Question 825822: Question 825655: -This winter, Mr.walker was out playing in the snow with the Walker-lers. The snow was great packing snow for snowballs, so they gathered up some neighbors and started to have friendly snowball fight. Mr.Walker went inside a friends apartment with a bucket of snowballs and started to launch them from the 4th floor window. He began to gather data on the snowball path so that he could have more accuracy when he threw them. One of the snowballs had a height(in feet)from the ground that followed the equation of +h%28t%29=+-16t%5E2%2B48t%2B64 how long does it take the snowball to reach the ground ? (Round to the nearest hundredth)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
When it hits the ground, +h%28t%29=0+
+-16t%5E2+%2B+48t+%2B+64+=+0+
+-t%5E2+%2B+3t+%2B+4+=+0+
+t+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
+t+=+%28-3+%2B-+sqrt%28+3%5E2+-+4%2A%28-1%29%2A4+%29%29+%2F+%282%2A%28-1%29%29+
+t+=+%28-3+%2B-+sqrt%28+9+%2B+16+%29%29+%2F+%28-2%29+
+t+=+%28-3+%2B-+sqrt%28+25+%29%29+%2F+%28-2%29+
+t+=+%28+-3+-+5+%29+%2F+%28-2%29+
( Use the negative square root to make the time positive )
+t+=+8%2F2+
+t+=+4+
In 4 seconds the snowball hits the ground
Here's the plot:
+graph%28+400%2C+400%2C+-1%2C+5%2C+-10%2C+120%2C+-16x%5E2+%2B+48x+%2B+64+%29+