Question

Solve application problems using radical equations. A hang glider dropped his cell phone from a height of 450 feet. How many seconds did it take for the cell phone to reach the ground?

Answer 1

Answer:

$\large \boxed{\text{5.29 s}}$

Step-by-step explanation:

The appropriate free fall equation is  

y = v₀t + ½gt²

Data:

v₀ = 0

g = 32.17 ft·s⁻²

Calculation:

$\begin{array}{rcl}450 &=& v_{0}t + \dfrac{1}{2}gt^{2}\\\\& = & 0 \times t + \dfrac{1}{2}\times 32.17t^{2}\\\\& = & 16.08t^2\\t^{2}& = & \dfrac{450}{16.08}\\\\& = & 27.97\\t & = & \textbf{5.29 s}\\\end{array}\\\text{It took \large \boxed{\textbf{5.29 s}} for the phone to reach the ground.}$