It is ambiguity that started and sustained this thread. If there can be multiple interpretations by professionals in the field, the question then becomes not whether the student uderstood the desired concept but rather whether the student read the questioners mind. What is being tested - physics or reading ability?
Bob at PC
________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu on behalf of John Clement
Sent: Sun 2/15/2009 12:25 AM
To: 'Forum for Physics Educators'
Subject: Re: [Phys-l] FCI answer?
In the statement for problems 8-11 it clearly states that V_k is the
velocity the puck would have starting from rest, and it clearly shows the
force in only one direction perpendicular to the initial motion. I missed
the problem statement because in the copy in Mazur's book it is on the
previous page. Mea culpa, that was my mistake. The problem statement is
exact and clear. Then only 1 trajectory is correct in problem 8, and when
you pick that, the answer to problem 9 is also clear. There is no
ambiguity.