Question

If an object is projected at a velocity of 129 ft per sec and its height = `-16t^2+129t.` What is its height after 5 seconds?

Answer 1

`"height" = 245` `"ft"`

Explanation:

We're asked to find the height of the projectile after a certain amount of time, given its height vs. time equation.

Well, let's plug `5` in for `t` in the `y(t)` equation:

`y(5) = -16(5)^2 + 129(5) = color(red)(ulbar(|stackrel(" ")(" "245color(white)(l)"ft"" ")|)`

Thus, after `5` `"s"`, the height of the projectile is `color(red)(245color(white)(l)"feet"`.