Answer:
53.33 mph
Explanation:
Speed is the rate of change of distance with time. Mathematically,
speed = distance/time
and is measured in miles per hour or meter per second.
To get the average speed over the entire trip, we must get the total time spent on trip and the total distance, then apply the speed formula
Time for the first 300 miles
= 300/60
= 5 hours
Time spent on the last 100
= 100/40
= 2.5 hours
Total time of the trip = 5 + 2.5
= 7.5 hours
Total distance covered
= 300 miles + 100 miles
= 400 miles
Average speed on the trip
= 400/7.5
= 53.33 miles per hour