Answer:
Part a) The expression is [tex]y=-8.5x[/tex]
Part b) -51 feet
Step-by-step explanation:
The complete question is
A whale descends 382.5 feet in 45 seconds.
The whale's elevation changes at a constant rate.
Part a) Write an expression that can be used to find the average elevation change of the whale during its descent in feet per second
Part b) What is the elevation change of the whale after 6 seconds?
Part a)
we know that
Find out the unit rate
To find out the unit rate divide the total elevation by the total time
Remember that
The sea level represent the level zero
If a whale descends, then the elevation is negative (below the sea level)
so
[tex]\frac{-382.5}{45}\ \frac{ft}{sec}=-8.5\ \frac{ft}{sec}[/tex]
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
[tex]y/x=k[/tex] or [tex]y=kx[/tex]
Let
x ----> the time in seconds
y ----> the elevation in feet
In this problem we have a proportional relationship, because the line passes through the origin (For x=0, y=0)
so
[tex]y=kx[/tex]
The value of the constant of proportionality k is equal to the unit rate or slope of the linear equation
[tex]k=-8.5\ \frac{ft}{sec}[/tex]
substitute
[tex]y=-8.5x[/tex]
Part b) For x=6 sec
substitute in the linear equation
[tex]y=-8.5(6)[/tex]
[tex]y=-51\ ft[/tex]
The expression that can be used to find the average elevation change of the whale during its descent in, in feet per second is s = 8.5t
The formula for average elevation in feet per second is the speed of the whale in feet per seconds
Given the following parameters
Distance = 382.5 feet
Times = 45 seconds'
Calculate the speed
Speed = Distance/Times
Speed = 382.5/45
Speed = 8.5ft/s
Recall that s = d/t
d = st
s = 8.5t
Hence the expression that can be used to find the average elevation change of the whale during its descent in, in feet per second is s = 8.5t
Learn more here: https://brainly.com/question/13262646
