Question

Revised experiment setup ty I-v A student wants to find out how much energy is lost by the string rubbing at the edge of the table when the system moves by 30cm. They come up with two methods to make this measurement: Method 1: Calculate work done on the string by the table, Wedge=(T1−T2)xWedge=(T1−T2)x Where T1 and T2 are the magnitude of the force measured by the top and hanging IOLabs, respectively. x is the distance traveled by the IOLabs, measured using the wheel of the top IOLab. Method 2: Conservation of energy, Wedge=12(m1+m2)v2f−m2gxWedge=12(m1+m2)vf2−m2gx Where m1 and m2 are the top and hanging masses, respectively, and vf is measured using the wheel of the top IOLab. x is the distance traveled by the IOLabs, measured using the wheel of the top IOLab. The student does four trials of their experiment and makes the following measurements: Trial T1 (Newtons) T2 (Newtons) vf (m/s) 1 1.059 1.571 1.698 2 1.088 1.707 1.718 3 1.082 1.695 1.678 4 1.047 1.827 1.698 Additionally, the student determines the displacement (x) was 30cm, m1 is 202g and m2 is 351g. 1) Using method 1, what is the average measurement of the work done by the edge of the table on the string? (This value is NOT a magnitude). Joules 2) What is the size of the uncertainty on the average measurement from Method 1? You should do your calculation using the method described in the class handout on uncertainty. Joules 3) Using method 2, what is the average measurement of the work done by the edge of the table on the string? (This value is NOT a magnitude). Joules 4) What is the size of the uncertainty on the average measurement from Method 2? Joules 5) Compare the results from the two methods. What should you conclude about them? a) The results from the two methods disagree with each other b) The results from the two methods do not disagree with each other c) It is impossible to make a decision about these results 6) Explain how you decided if the two measurements agree or not. If they do not agree, identify a relevant assumption from the experiment that could cause the disagreement.

Answer 1