The function [tex]$h(t) = -16t^2 + 28t + 500[tex]$[/tex] represents the height of a rock [tex]$[/tex]t[tex]$[/tex] seconds after it is propelled by a slingshot. What does [tex]$[/tex]h(3.2)$[/tex] represent?

A. The height of the rock 3.2 seconds before it reaches the ground
B. The time it takes the rock to reach the ground, or 3.2 seconds
C. The time it takes the rock to reach a height of 3.2 meters
D. The height of the rock 3.2 seconds after it is propelled



Answer :

To solve the problem, we need to evaluate the function \( h(t) = -16t^2 + 28t + 500 \) at \( t = 3.2 \).

Here is the step-by-step process:

1. Understand the problem: We are given a function \( h(t) \) that represents the height of a rock \( t \) seconds after it is propelled. We need to find out what \( h(3.2) \) represents.

2. Substitute \( t = 3.2 \) into the function:
[tex]\[ h(3.2) = -16(3.2)^2 + 28(3.2) + 500 \][/tex]

3. Evaluate the function at \( t = 3.2 \):
[tex]\[ h(3.2) = -16 \cdot 10.24 + 28 \cdot 3.2 + 500 \][/tex]
[tex]\[ h(3.2) = -163.84 + 89.6 + 500 \][/tex]
[tex]\[ h(3.2) = 425.76 \][/tex]

4. Interpret the result: The value \( h(3.2) = 425.76 \) represents the height of the rock when \( t = 3.2 \). Therefore, it indicates the height of the rock 3.2 seconds after it is propelled.

Based on this interpretation, we can conclude:

The correct answer is:
- the height of the rock 3.2 seconds after it is propelled