deepak manchanda
Jun 11, 2007, 03:02 AM
A body covers half a distance with a speed of 20m/s and the other half with a speed of 30m/s.Find the average speed of the whole journey?
Capuchin
Jun 11, 2007, 09:07 AM
Deepak, consider a test piece of road. A good length of road to choose would be one that is easily divisible by both your speeds, like 120m.
So he travels 60m at 20m/s and 60m at 30m/s
What is the total time he takes? What is the total distance? Therefore what's his average speed?
Let me know if you have any trouble.
colbtech
Jun 11, 2007, 01:34 PM
Ah thanks for the explanation, see where my "expert" guess falls down!