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# quick physics question watch

1. A man cycles to work with the wind at 8.0 m/s and returns home against the wind at 4 m/s. What is his average speed? (hint:It is not 6 m/s)

I'm probably missing something obvious ?
thanks
2. are you sure it's speed and not velocity?
3. (Original post by cardine92)
are you sure it's speed and not velocity?
100% lol
thats why im confused. any ideas ?
4. 5.3 ms-1
5. want to know why or want to work it out your self?
6. (Original post by Katermerang)
want to know why or want to work it out your self?
7. Ok well lets write down the basics first:

Speed= Distance/time

Distance = d
Time to work=T1
Time back = T2

so you can write two equations form this data to work out the two individual speeds (to work and back)

8= d/T1 and 4= d/T2

Now Average speed = total distance/total time

so a rearrangement of the top equations gives:

Average speed = [2d] / [ (d/8) + (d/4)]

The "d"s cancel out leaving you with (16/3) or 5.3ms-1

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