Answer:
Norma’s average speed is 41.9 km/h.
Explanation:
The average speed is given by:
[tex] \overline{v} = \frac{d_{T}}{t_{T}} [/tex]
Where:
[tex]d_{T}[/tex]: is the total distance
[tex]t_{T}[/tex]: is the total time
We can find the total distance as follows:
[tex] d_{T} = v_{1}*t_{1} + v_{2}*t_{2} = 40 \frac{km}{h}*150 min*\frac{1 h}{60 min} + 60 \frac{km}{h}*3.15 h = 289 km [/tex]
Now, the total time is:
[tex] t_{T} = t_{1} + t_{2} + t_{3} = 150 min*\frac{1 h}{60 min} + 75 min\frac{1 h}{60 min} + 3.15 h = 6.9 h [/tex]
Hence, the average speed is:
[tex] \overline{v} = \frac{d_{T}}{t_{T}} = \frac{289 km}{6.9 h} = 41.9 km/h [/tex]
Therefore, Norma’s average speed is 41.9 km/h.
I hope it helps you!
