Question

a crane is lowering a concrete block from a height of 500 feet above the ground at a constant rate of 4.5 feet per second. which function can be used to determine h, the height, in feet, above the ground of the concrete block after x seconds?
$h = -4.5s + 500$
$h = 500s + 4.5$
$h = 500s - 4.5$
$h = 4.5s - 500$

Explanation:

Step1: Identify initial height

The initial height is 500 feet, this is the y-intercept.

Step2: Identify rate of change

The height decreases at 4.5 ft/s, so slope is -4.5.

Step3: Match to linear function

Linear form: $h = (\text{slope})x + \text{initial height}$. Replace $x$ with $s$ (variable used in options): $h = -4.5s + 500$.

Answer:

A. $h = -4.5s + 500$