Probing the misconception:

 Students fail to see acceleration as the ratio Dv/Dt.

References Description

 

Below is a diagram of a train that uniformly accelerates from rest to point A, and then travels at a constant speed. Students are asked to calculate the acceleration of the train before reaching point A using the distances and times given. Do not provide them with the kinematic equations.

 

 

 

 Correct Answer

Students who suffer from this difficulty will tend to arbitrarily divide one of the distances by one of the times to arrive at a velocity. They will then divide by time again (perhaps the same time interval, perhaps the other) to arrive at an "acceleration."

 

 

 

 


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