Physics puzzle

[star882]

There is a circular running track 168 feet in diameter. Peggy Liska runs 10 laps around the track in 6 minutes. What is her average velocity in meters per second?

Hint: Circumference is equal to diameter times pi. One meter is about 3.28 feet. One minute is 60 seconds.

[frank]

4.46860139m/s

[geniushem]

8.5 m/sec.. am i write if not how to proceed...

[paul_h]

8.5 m/sec.. am i write if not how to proceed...

No the previous poster is right.
168/3.28 =51.21m
51.22 x 3.14 = 160.83 m track circumference
10 laps = 1608.308 meters total ran
total time is 6 min = 360 secs
speed = distance divide time
1608.83/360 = 4.47meters per second
This was all rounded up though to 2 decimal places, just to show the numbers posted here would equal the result posted here. When I first did it using mscalc.exe I didn't do any rounding and got a more exact answer.

[Plank!]

Zero? It is a circular track after all...

[kaon]

Zero? It is a circular track after all...

I agree that the runner's average velocity is zero if the start and end locations are the same.
It's kind of a trick question... How else to explain the quaint usage of the word "velocity" instead of speed? And why the original poster described it as a "puzzle" rather than a "homework problem".

[Plank!]

I agree that the runner's average velocity is zero if the start and end locations are the same.
It's kind of a trick question... How else to explain the quaint usage of the word "velocity" instead of speed? And why the original poster described it as a "puzzle" rather than a "homework problem".

Exactly!

I was asked a similar question in a physics exam many years ago.
Velocity is a linear quantity, so any circular movement must have zero "average" velocity

The answer is in the question