Difference between revisions of "Post-practice reflection"

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&nbsp; &nbsp; <br>ANDES PROBLEM ROTS4A: A 5.00 kg ball is attached to a 2.00 m rope which will break if the tension exceeds 100 N. If the ball is made to swing in a vertical circle, what is the maximum velocity with which the ball can pass through the lowest point?<br>
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&nbsp; &nbsp; <br>ANDES PROBLEM ROTS4A: A 5.00 kg ball is attached to a 2.00 m rope which will break if the tension exceeds 100 N. If the ball is made to swing in a vertical circle, what is the maximum velocity with which the ball can pass through the lowest point?<br><br>
  
 
&nbsp; &nbsp; TUTOR: Which major principle did you need to solve the problem? [Just the name, please]<br>
 
&nbsp; &nbsp; TUTOR: Which major principle did you need to solve the problem? [Just the name, please]<br>
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&nbsp; &nbsp; STUDENT: Newton's 2nd law<br>
 
&nbsp; &nbsp; STUDENT: Newton's 2nd law<br>
  
&nbsp; &nbsp; We know that there is an electric field. If there is an electric field, <br> and there is a charged particle located in that region, then we can infer <br> that there is an electric force on the particle. The direction of the <br> electric force is in the opposite direction as the electric field because <br> the charge on the particle is negative.
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&nbsp; &nbsp; TUTOR: Yes. The main difference between this problem and most of the previous N2L problems is the fact that the direction of acceleration is __________. (fill in the blank)<br>
  
&nbsp; &nbsp; We use the Force tool from the vector tool bar to draw the electric force. <br> This brings up a dialog box. The force is on the particle and it is due to some <br> unspecified source. We do know, however, that the type of force is electric, so <br> we choose “electric” from the pull-down menu. For the orientation, we need to <br> add 180 degrees to 22 degrees to get a force that is in a direction that is <br> opposite of the direction of the electric field. Therefore we put 202 degrees. <br> Finally, we use “Fe” to designate this as an electric force.
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&nbsp; &nbsp; STUDENT: centripetal
  
<center>[ PROMPT ]</center>
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&nbsp; &nbsp; Now that the direction of the electric force has been indicated, we can work on <br>finding the magnitude. We must choose a principle that relates the magnitude <br> of the electric force to the strength of the electric field, and the charge on the <br> particle. The definition of an electric field is only equation that relates these <br> three variables. We write this equation, in the equation window.
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<center>[ PROMPT ]</center>
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Note. PROMPT = "Please begin your self-explanation."
 
  
  

Revision as of 14:18, 13 January 2008

Brief statement of principle

Post-practice reflection involves activities that follow successful completion of a quantitative problem aimed at helping students to understand the concepts associated with that problem and to develop abstract problem-solving schema. Such schema are a kind of knowledge component that if acquired with high feature validity will help students with solving similar (near transfer) problems, and perhaps also far-transfer problems.

Post-practice reflection activities often involve some kind of dialogue between the student and another agent (teacher, peer, or computer tutor).

Examples

Here is a sample Reflective Dialogue, incorporated within the Andes physics tutoring system (VanLehn et al., 2005):


An example of a Post-Practice Reflective Dialogue

   
ANDES PROBLEM ROTS4A: A 5.00 kg ball is attached to a 2.00 m rope which will break if the tension exceeds 100 N. If the ball is made to swing in a vertical circle, what is the maximum velocity with which the ball can pass through the lowest point?

    TUTOR: Which major principle did you need to solve the problem? [Just the name, please]

    STUDENT: Newton's 2nd law

    TUTOR: Yes. The main difference between this problem and most of the previous N2L problems is the fact that the direction of acceleration is __________. (fill in the blank)

    STUDENT: centripetal