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Question
A train takes 2 h to reach station B from station A, and then 3 h to return from station B to station A. The distance between the two stations is 200 km. Find:
The average speed,
The average velocity of the train.
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Solution
Here, total distance = (200 + 200) km = 400 km
Total time taken = (2 + 3) h = 5 h
(i) Average speed = Total distance travelled/total time taken = `(400 "km")/(5 "h")` = 80 km h-1
(ii) Average velocity of the train is zero because the train stops at the same point from where it starts, i.e. the displacement is zero.
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