Answer:
Journey A average speed is 19.86 meters per second
Journey B average speed is 13.68 meters per second
Step-by-step explanation:
The average speed is defined as the distance divided by the time, so that's what we have to do. But first, let's convert the time in seconds and the distance in meters, because we have to answer in meters per second:
Journey A:
2 hours = 120 minutes. Each minute have 60 seconds, so 120•60= 7200 seconds.
143 km = 143000 meters
143000/7200 = 19.86 m/s
Journey B:
3 hours = 180 minutes + 15 minutes = 195 minutes
195•60 = 11700 seconds
160 km = 160000 meters
160000/11700 = 13.68 m/s