Pam W. answered • 09/16/14
Tutor
4.9
(123)
BS Mathematics/Secondary Education Certificate with 4 years teaching
Hello Kendall,
In order to find an average speed we need to find the total distance traveled and the total time traveled.
Total Distance = 100 km + 200 km = 300 km
Total Time = 2 hrs + 4 hrs = 6 hrs
Now divide the total distance by the total time to get the average speed.
300 km/6 hrs = 50 km/hr
The half hour break would not count toward the travel time and distance of the car.
Hope this helps,
Pam W.
Kendall B.
Thank you so much Pam. Can you answer my other question if you can?
A car travels 100 km in the first two hours, stops for half an hour and then travels 200 km in the next four hours. Find the average speed of the car.
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09/16/14
Arthur D.
tutor
Taking the 1/2 hour into consideration doesn't seem to make sense in determining the average speed. Suppose after traveling 100 km the driver stops at a motel and stays there for 12 hours, say, overnight. The next morning the driver travels the other 200 km. The total distance is 300 km and the total time is 2+4+12=18 hours.
300/18=16 2/3 km per hr for the average speed doesn't seem right.
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09/16/14
Kendall B.
Thank you Arthur!
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09/16/14
Arthur D.
tutor
You're welcome, Kendall.
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09/16/14
Philip P.
Since you are taking an average, you need to take all data points into account, including ones that may equal zero. The 1/2 hour stop should be included. It took the driver 6.5 hours to travel 300 miles for an average speed of 46.2 mph.
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09/17/14
Philip P.
09/16/14