On 2007 Mar 13 , at 11:43 AM, STANLEY DOORE wrote:
The test example ...
They should have questions using the SI in science applications.
----- Original Message ----- From: "Howard Ressel"
<[EMAIL PROTECTED]>
For example, Sally walked 200 m Bill walked 2 km, how far did
they walk together.
Metric aside, I have another point to quibble with on that question
about the two people and their walk together.
What does the word "together" mean in this case? If that means the
two people were walking side-by-side, perhaps holding hands, then the
distance they "walked together" must be only 200 m. At the end of
that 200 m, Sally stopped (since the problem says she only walked 200
m) while Bill must have continued walking WITHOUT HER, since he
walked 2000 m. The only walked "together" for 200 m. (Or do Sally and
Bill each have 900 m long arms, allowing them to still be holding
hands after Bill has walked 1800 m further than Sally?!)
Apparently the author of the question wanted the students to add 200
m and 2 km (converted to 2000 m) to get 2200 m (or do it all in
kiiometres and get 2.2 km). But what physical reality is there to
adding together the separate distance of two separate walks? (If the
question further stipulated that Sally and Bill were walking toward
each other along a straight line, then the question "How far apart
were they if met after Sally walked 200 m and Bill walked 2 km?"
would be a reasonable question to ask. But "walked together"? It's
ambiguous at least (what does it mean?), and impossible at worst
(they have arms 900 m long).
We do our students no service trying to teach them metric by using
questions that are unambiguous or describe illogical situations
Bill Hooper
1810 mm tall
Fernandina Beach, Florida, USA
