A phone is accidentally dropped from a helicopter at a height of [tex]$3,600 \, \text{ft}$[/tex]. If the equation for height as a function of time is [tex]$h(t) = -16t^2 + \text{initial height}$[/tex], where [tex]$t$[/tex] is time in seconds and [tex]$h(t)$[/tex] is height in feet, how many seconds will it take for the phone to hit the ground?

[?] seconds



Answer :

To determine how many seconds it will take for the phone to hit the ground when dropped from a height of 3,600 feet, we start with the given height equation:
[tex]\[ h(t) = -16t^2 + \text{initial height} \][/tex]

Here:
- [tex]\( h(t) \)[/tex] is the height of the phone at time [tex]\( t \)[/tex] in seconds.
- The initial height is 3,600 feet.
- The phone hits the ground when [tex]\( h(t) = 0 \)[/tex].

Let's set up the equation with these values:

[tex]\[ 0 = -16t^2 + 3600 \][/tex]

Now, we need to solve this equation for [tex]\( t \)[/tex].

1. Move the constant term to the other side of the equation:

[tex]\[ 16t^2 = 3600 \][/tex]

2. Divide both sides by 16 to isolate [tex]\( t^2 \)[/tex]:

[tex]\[ t^2 = \frac{3600}{16} \][/tex]

3. Simplifying the fraction:

[tex]\[ t^2 = 225 \][/tex]

4. Take the square root of both sides to solve for [tex]\( t \)[/tex]:

[tex]\[ t = \sqrt{225} \][/tex]

5. Taking the square root of 225 gives:

[tex]\[ t = 15 \][/tex]

Thus, it will take the phone 15 seconds to hit the ground. The intermediate values confirm this result:
- Intermediate calculation for [tex]\( \frac{3600}{16} \)[/tex] gives 225.
- Taking the square root of 225 results in 15.

So, the phone will hit the ground in:
[tex]\[ 15 \text{ seconds} \][/tex]