Question

please help with these questions on significant figures and uncertainty

Determining Sample Uncertainty (Frequently this semester, we will skip this step to concentrate on other concepts in lab) For help: see How do I find the uncertainty in a measurement? Part 2: Sample Uncertainty 8. A student made the following nine measurements of the wavelength of a standing wave: 7= 14.4 cm, 15.1 cm, 14.2 cm, 14.6 cm, 14.4 cm, 14.8 cm, 13.7 cm, 13.9 cm, 14.9 cm. Assume the instrumental uncertainty is 0.1 cm. The average of the measurements is approximately 14,4 cm, so we will make that value our best estimate of the wavelength of the standing wave. What is a reasonable estimate of the sample uncertainty? Include units. Show work Determining "overall" uncertainty For help: see How do I find the uncertainty in a measurement? Part 3: "overall" uncertainty 9. A student was measuring the wavelength of standing waves using a meter stick. The student decided that the meter stick had an instrumental uncertainty of 0.5 mm and the standing waves had a sample uncertainty of 1.0 cm. What is the uncertainty in the measurement (i.e., the "overall" uncertainty) of the wavelength of the standing waves? Include units, [1 cm = 10 mm

Answer 1

Solution I wave length of a standing ware - 14.4cm, 15.1 cm, 19.6 cm, 14.4cm, 14 8 cm 137 cm, 13.9 cm 14.9cm, 14.2 cm Avarage measure ment i = 14.4 cm we have to find out the Avarge of squp goue square square of of the measun the measured values Ba 207.36 t ra.yom) 12 = (14.4 m2 = 207-36 con? (15.092 = 228.01 cm? (14.6² = 213.16 cm (14.43 = 207.36 com 2 (1418) = 219.04 cm² (13.7) = 187.69 con [13.9² - 193.21 cm² 14.9)2 = 222.01.cm? (14.29² = 201.64 cm2 Lit) = 208.83 standand deviation in measure ment=0 208-83 - 207.36 - 1.21 cm Instrumental un sentainty = 0.1 cm sample uncentrainty = 1.21 cm (6) So, 00 h - + L (6.1xr2 = 0.121 cm) proved)