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secondary 4 | E Maths
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Please help with this question
Date Posted: 5 years ago
Views: 218
Easiest is to call a distance of say 10 km.
20 km/h for 5 km and 25 km/h for 5 km.
That’s (5 / 20 x 60) = 15 min for the first 5 km and (5 / 25 x 60) = 12 min for the next 5 km.
Total distance is 10 km and total time is 27 min.
Average speed = (10 / 27 x 60) = your answer in km/h.
20 km/h for 5 km and 25 km/h for 5 km.
That’s (5 / 20 x 60) = 15 min for the first 5 km and (5 / 25 x 60) = 12 min for the next 5 km.
Total distance is 10 km and total time is 27 min.
Average speed = (10 / 27 x 60) = your answer in km/h.
We cannot just take the average of the two speeds. In general, we cannot the average out of two speeds to obtain the average speed.
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