### Home > PC > Chapter 8 > Lesson 8.2.1 > Problem 8-77

8-77.

If a ball is thrown vertically upward with a velocity of 32 ft/s, its height after *t* seconds is given by the equation *s* = 32*t* −16*t* ^{2}. At what instant will the ball be at its highest point, and how high will it rise? Homework Help ✎

1. Set the function = 0.

2. Factor.

3. Solve for the *t*-intercepts.

4. Take the average of the *x*-intercepts to locate the *t*-coordinate of the vertex.

5. Substitute that *t*-value into the original equation to calculate the maximum height.