I asked students to write about what forces must be balanced when a box is pushed across a floor at constant speed. Here is what one student wrote.
At a constant speed, the force of gravity pulling the object down must balanced the force of the floor pushing the object up.
Same student responds to what was confusing about the reading:
Do balanced forces have to be equal or “canceling out” forces? In the first question, if I’m constantly pushing the object at the same speed then the my force on the object is higher then the force of friction on the object. but my force stays constant and the lesser force of friction stays constant. I wanted to add this to my anwser on the first question but was a bit confused.
This is so important. The first question invoked in this student a response like, “Get down a correct thing you read from the text, and don’t risk getting it wrong by putting down what you actually think.” The second question invoked a different response, more like “Tell the instructor what you are really thinking and ask a question about how that thinking relates to the reading.
As instructors, these are some question we should always be thinking about: How are our students framing tasks of responding to the questions we pose? Are they looking to get correct stuff down and avoid getting incorrect stuff down, or are they honestly engaging in a dialogue between their ideas and the ideas they are encountering. How do we know whether its one or the other? How do support a culture of the second?