Answer:
a.52.9 km/h
b.90 km
Explanation:
We are given that
[tex]v_1=89km/h[/tex]
[tex]t_1=30min[/tex]
[tex]v_2=100km/h[/tex]
[tex]t_2=12min[/tex]
[tex]v_3=40km/h[/tex]
[tex]t_3=45 min[/tex]
Time spend on eating lunch and buying ga=15 min.
a.Total time=30+12+45+15=102 minute=[tex]\frac{102}{60}=1.7 hour[/tex]
1 hour=60 minutes
Distance=[tex]speed\times time[/tex]
[tex]d_1=v_1\times t_1=80\times\frac{30}{60}=40km[/tex]
[tex]d_2=100\times \frac{12}{60}=20 km[/tex]
[tex]d_3=40\times \frac{45}{60}=30 km[/tex]
Total distance=[tex]d_1+d_2+d_3=40+20+30=90km[/tex]
Average speed=[tex]\frac{total\;speed}{total\;time}[/tex]
Using the formula
Average speed=[tex]\frac{90}{1.7}=52.9Km/h[/tex]
b.Total distance between the initial and final city lies along the route=90 km
