I have a problem with the very first experiment. In my opinion, its educational value needs to be re-examined because it unintentionally conveys the wrong message to the student(s) who perform it. One is asked to measure the constant velocity of a trolley moving down an inclined ramp.
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The intended educational value of this "experiment" is to establish in the student's mind the idea that equal spacings on the in equal distances.
OK, but what will you, as a teacher, say to a student who puts a piece of chalk on the incline and watches it roll downhill starting from rest? Here is my imagined dialogue.
Student: Is the chalk not accelerating?
You: Of course it is. It is initially at rest and then, at a later point, it is moving faster and faster.
Student: Then how come the trolley is moving at constant velocity on the same incline?
You: This is an idealisation. The trolley would normally accelerate when placed on the incline. However, friction on the tape that it being dragged, air resistance, friction at the wheels' axles etc. provide an opposing force to the downhill component of gravity. If the trolley were on a horizontal surface in this setup, it would decelerate and stop. We need the incline to compensate for the dissipative forces.
@kuruman's recommendations (free of charge)
Toss this experiment because it hides the truth and reinforces the incorrect idea that something rolling down an incline can do so at constant velocity. Since photogates are available for these experiments, use them instead with commercially available photogate picket fences. Rewrite the first two experiments.
