Question

a paratrooper jumps from a plane at an altitude of 4500 ft and descends at the rate of 20 ft/sec. what is the paratroopers height, h, above the ground after t seconds?
a. $h = \frac{4500}{20} - t$ c. $h = 4500 + 20t$
b. $h = -20t + 4500$ d. $h = \frac{4500}{20}t$
please select the best answer from the choices provided
\bigcirc a
\bigcirc b
\bigcirc c
\bigcirc d

Explanation:

Step1: Analyze the problem

The paratrooper starts at an altitude of 4500 ft (initial height) and descends at a rate of 20 ft/sec. So the height \( h \) above the ground should decrease as time \( t \) increases. The general form of a linear equation is \( h = mt + b \), where \( m \) is the slope (rate of change) and \( b \) is the initial value.
Here, the initial height \( b = 4500 \) ft, and the rate of descent (so the slope \( m \)) is -20 ft/sec (negative because height is decreasing).

Step2: Form the equation

Substituting \( m = -20 \) and \( b = 4500 \) into the linear equation \( h = mt + b \), we get \( h=-20t + 4500 \).

Answer:

B. \( h=-20t + 4500 \)