Question

9. A car has an average speed of 80 km/h for one hour, then an

average speed of 90.0 km/h for two hours during a three-hour
trip. What was the average speed for the three hour trip?

Answer 1

86.67 km/hr

Explanation:

First Hour: (80 km/hr)(1 hr) = 80 km

Next two hours: (90 km/hr)(2 hr) = 180 km

Total distance traveled: = 260 km

Average speed: total distance / total time elapsed) = 260 km / 3 hr

= 86.67 km/hr