Answer:
39.77 m/s
Step-by-step explanation:
We are given that
Average speed of Moe for first hour=42 mph
They stop car for gas for 10 minutes
Average speed of Joe for 40 minutes=31 mph
After traffic clear
Average speed of Joe fro half hour=60 mph
We have to find the average speed of car on his trip.
1 hour=60 minute
Total time =60+10+40+30=140 minutes
Time=[tex]\frac{140}{60}=2.33 hours[/tex]
We have to find total distance
Distance covered when average speed 42 mph=[tex]speed\times time=42\time 1=42 mi[/tex]
Distance covered when average speed 31 mph=[tex]31\times \frac{40}{60}=20.67 mi[/tex]
Distance covered when average speed 60 mph=[tex]60\times \frac{30}{60}=30 mi[/tex]
Total distance=42+20.67+30=92.67 mi
Average speed =[tex]\frac{distance}{time}=\frac{92.67}{2.33}=39.77 m/s[/tex]
Hence, average speed on this trip=39.77 m/s
