A faucet is used to add water to a large bottle that already contained some water. After it has been filling for 5 seconds, the gauge on the bottle indicates that it contains 17 ounces of water. After it has been filling for 11 seconds, the gauge indicates the bottle contains 35 ounces of water. Let [tex][tex]$w$[/tex][/tex] be the amount of water in the bottle [tex]$t$[/tex] seconds after the faucet was turned on. Write a linear equation that models the amount of water in the bottle in terms of [tex]$t$[/tex].

Select a single answer:
[tex]\[
\begin{array}{ll}
A. & w = 3t + 2 \\
B. & w = \frac{1}{3}t + \frac{46}{3} \\
C. & w = -3t + 32 \\
D. & w = 3t + 2 \\
\end{array}
\][/tex]



Answer :

To find the linear equation that models the amount of water [tex]\( w \)[/tex] in the bottle in terms of the time [tex]\( t \)[/tex], we need to determine the slope (rate of water flow) and the y-intercept (initial amount of water in the bottle before we start timing).

1. Calculate the rate of water flow (slope, [tex]\( m \)[/tex]):
We are given the following data points:
- At [tex]\( t = 5 \)[/tex] seconds, [tex]\( w = 17 \)[/tex] ounces.
- At [tex]\( t = 11 \)[/tex] seconds, [tex]\( w = 35 \)[/tex] ounces.

The slope ([tex]\( m \)[/tex]) can be calculated using the formula for the rate of change:
[tex]\[ m = \frac{\Delta w}{\Delta t} = \frac{w_2 - w_1}{t_2 - t_1} \][/tex]
Substituting the given values:
[tex]\[ m = \frac{35 - 17}{11 - 5} = \frac{18}{6} = 3 \][/tex]
So, the rate of water flow is [tex]\( 3 \)[/tex] ounces per second.

2. Determine the initial amount of water (y-intercept, [tex]\( b \)[/tex]):
To find the y-intercept [tex]\( b \)[/tex], we use one of the data points and the slope we just found. We use the point [tex]\( (t_1, w_1) = (5, 17) \)[/tex]:
[tex]\[ w = mt + b \][/tex]
Plug in [tex]\( t = 5 \)[/tex], [tex]\( w = 17 \)[/tex], and [tex]\( m = 3 \)[/tex]:
[tex]\[ 17 = 3(5) + b \][/tex]
[tex]\[ 17 = 15 + b \][/tex]
Solving for [tex]\( b \)[/tex]:
[tex]\[ b = 17 - 15 = 2 \][/tex]
So, the initial amount of water in the bottle is [tex]\( 2 \)[/tex] ounces.

3. Form the linear equation:
Combining the slope ([tex]\( m \)[/tex]) and the y-intercept ([tex]\( b \)[/tex]), the linear equation that models the amount of water [tex]\( w \)[/tex] in the bottle in terms of time [tex]\( t \)[/tex] is:
[tex]\[ w = 3t + 2 \][/tex]

Therefore, the correct equation that models the amount of water in the bottle is:
[tex]\[ w = 3t + 2 \][/tex]

The correct answer is:
[tex]\[ w = 3t + 2 \][/tex]