Question 825822
When it hits the ground, {{{ h(t)=0 }}}
{{{ -16t^2 + 48t + 64 = 0 }}}
{{{ -t^2 + 3t + 4 = 0 }}}
{{{ t = (-b +- sqrt( b^2 - 4*a*c )) / (2*a) }}}
{{{ t = (-3 +- sqrt( 3^2 - 4*(-1)*4 )) / (2*(-1)) }}}
{{{ t = (-3 +- sqrt( 9 + 16 )) / (-2) }}}
{{{ t = (-3 +- sqrt( 25 )) / (-2) }}}
{{{ t = ( -3 - 5 ) / (-2) }}}
( Use the negative square root to make the time positive )
{{{ t = 8/2 }}}
{{{ t = 4 }}}
In 4 seconds the snowball hits the ground
Here's the plot:
{{{ graph( 400, 400, -1, 5, -10, 120, -16x^2 + 48x + 64 ) }}}