Answer:
Justin's displacement is 12.65 km.
Step-by-step explanation:
Since Justin rides 12 km south, then 4 km west, his displacement can be determined by applying Pythagoras theorem to the sketch of his journey. Let his displacement be represented by s,
=
+
=
+
= 16 + 144
= 160
⇒ s =
= 12.6491
s ≅ 12.65 km
Justin's displacement is 12.65 km.
To write an equation for this line, you first need to understand how to derive it.
Let's utilize slope-intercept form, as it's the easiest to understand compared to any other form for line functions:
y = mx + b
m: The slope of the line
b: The y-intercept (The point where the line is at the y-axis)
Now that we've defined our variables, how do we go about making the actual equation? Let's start off with the slope, m.
The slope is a measure of how high or low the line is. The number is a ratio between the rise and run of a slope. In other words, it is essentially
Let's look back at the graph. In the time interval from 1 to 2 seconds, we see that the line rises by 22 feet. Because the time interval is only 1 second, the run is 1 second.
Therefore:
m =
m =
m = 22
We now have the first variable of the equation.
y = 22x + b
What about b? As we established earlier, b is the value of coordinate y at the y-intercept. Essentially, to find b we need to know what the value of y is when the coordinate x is 0.
As you can see from the graph you made, the value of y when x is 0 is also 0. This makes sense, too. How can the cheetah travel distance at 0 seconds when it obviously hasn't started moving? We now know b = 0. Now, we have gotten all of the variables we need to make a full equation:
y = 22x + 0
y = 22x
If you'd like me to explain how I did anything, just ask!
- breezyツ