Respuesta :
Answer:
- Corey's max speed is [tex] 7 \frac{m}{s}[/tex]
- the distance Corey's covers in z seconds is [tex] 7 \frac{m}{s} * z \ s[/tex]
- [tex]d (z) = 45 m + 7 \frac{m}{s} * z[/tex]
- [tex]d (x) = 45 m + 7 \frac{m}{s} * (x-7 s)[/tex]
Explanation:
Corey's max speed
For constant speed, we know:
[tex]v=\frac{distance}{time}[/tex]
The distance between the 80 meters and the 45 meters is:
[tex]distance = 80 m - 45 m = 35 m[/tex]
and the time it took to reach the 80 meter will be:
[tex]time = 12 s - 7 s = 5 s[/tex]
So, Corey's max speed is
[tex]v_{max}=\frac{35 m}{5 s} = 7 \frac{m}{s}[/tex]
How far runs Corey
As the velocity of Corey's is [tex]v_{max}[/tex], the distance Corey's covers in z seconds is
[tex]distance = v_{max} * z \ s[/tex]
[tex]distance = 7 \frac{m}{s} * z \ s[/tex]
What is Corey's distance from the starting line
At time 7 + z seconds the distance will be the 45 meters he covers in the first part of the race plus the distance he traveled at constant speed. this is:
[tex]d (z) = 45 m + v_{max} * z[/tex]
[tex]d (z) = 45 m +7 \frac{m}{s} * z[/tex]
At time x ( x greater or equal to 7 seconds) the distance will be the 45 meters he covers in the first part of the race plus the distance he traveled at constant speed. this is:
[tex]d (x) = 45 m + v_{max} * (x-7 s)[/tex]
[tex]d (x) = 45 m + 7 \frac{m}{s} * (x-7 s)[/tex]