Question 133090
Given: {{{h=5t^2+Vot}}}

We are given an initial height of 250M and and an initial velocity of 25.

So the question is, how long does it take to go 250 meters?

{{{h=5t^2+Vot}}}
{{{250=5t^2+25t}}}
{{{0 = 5t^2 + 25t - 250}}}
{{{0 = t^2 + 5t -50}}}
{{{0 = (t +10) (t -5)}}}
Setting each factor equal to o yields t = -10 AND t = 5.

Since time can't be negative, the answer must be 5 seconds.

Check you answer.
{{{h=5t^2+25t}}}
{{{h=5(5)^2+25(5)}}}
{{{h = 125 + 125}}} = 250 which is the total distance to the ground