### Home > CALC > Chapter 5 > Lesson 5.2.3 > Problem 5-81

5-81.

Evaluate *v*(*t*) when *t* = 0.

Evaluate *h*(*t*) when *t* = 0.

Since the height function is a parabola, the maximum height can be determined by using Algebra to locate the vertex. Calculus can also be used.

The maximum height will occur at the time when *v*(*t*) = 0.

The vertex of the parabola is located at *t* = –21/2(–4.9) ≈ 2.143 seconds.*h*(2.143) ≈ 25.5 m