Answer:
Speed= 6 m/s
Velocity=-6 m/s or 6 m/s to the left
Explanation:
Speed is a scalar quantity and is always positive, while velocity is a vector; hence it must have a direction and a module (the speed).
In other words, the speed is the module of te velocity vector.
In this sense, average velocity [tex]V[/tex] and average speed [tex]S[/tex] are defined as:
[tex]V=\frac{\Delta X}{\Delta t}[/tex] (1)
Where [tex]\Delta X[/tex] is the object's variation in position and [tex]\Delta t[/tex] is the time
[tex]S=\frac{d}{t}[/tex] (2)
Where [tex]d[/tex] is the distance traveled and [tex]t[/tex] is the time of travel
Now, according to the given information, the person started at an initial position [tex]X_{o}=29 m[/tex] and finished at a final position [tex]X_{f}=2 m[/tex].
This means the variation in position [tex]\Delta X[/tex] (assuming the person is moving along the X-axis or horizontally) is:
[tex]\Delta X=X_{f} - X_{o}= 2 m - 29 m[/tex]
[tex]\Delta X=-27 m[/tex]
And [tex]\Delta t=4.5 s[/tex]
Then, the average velocity is:
[tex]V=\frac{-27 m}{4.5 s}[/tex] (3)
[tex]V=- 6 m/s[/tex] (4) As we can see, the negative sign indicates the direction, which is to the left (or to the West if the person is traveling along a West-East highway, for example)
On the other hand, if we calculate the distance traveled by this person we have to take the difference between the two points:
[tex]d=29 m - 2 m = 27 m[/tex]
As we know the time of travel [tex]t[/tex] is also [tex]4. 5 s[/tex], the average speed is:
[tex]S=\frac{27 m}{4.5 s}[/tex] (4)
[tex]S=6 m/s[/tex] (5)
