Measuring Static Friction of Glass with a Coin - Lab Experiment

The purpose of this lab is to measure a quantity related to the static friction of glass. Staticfriction is the force required to start moving an object from rest. You will place a coin on the glass and lift one end until the coin begins to move. Your goal is to measure the angle at which the coin moves and understand what affects the precision and accuracy of your measurements.1)Pick a coin to usebased onyour birth month and thelist here:Jan – March$0.05Apr – June$0.10July– Sept$0.25Sept – Dec$1.002)Place the coin“headsup” (with the persons head facingup) flat on a horizontal surface made of glass (could be a mirror, tablet, smartphone screen, etc.). Keep one end fixed and elevate the other end slowlyuntil the coin moves (watch carefully as the coin may move suddenly or very slowly).3)Stop moving the surface.4)Measure the inclination angle (the angle from your table to the surface you’ve used). Do this by measuring the height of the raised surface and the length of the surface to infer the angle by a well known trigonometric identity.5)Considering your measuring technique and device, estimate the uncertainty in the angle. You may assume that the percent uncertainty in the sine of the angle is equal to the percent uncertainty of the angle itself.6)Repeat this measurement (including uncertainties) a total of 5 times.7)Tabulate your data (include absolute uncertainties):Trial #LengthHeightAngle12345
48)Compute the average angle and average uncertainty. Compute the difference betweenthe measured angles in each trial and the averaged angle. Quantitatively how do the differences compare to the average uncertainty?9)Based on 8) would you say that the average uncertainty accounts for the different trialmeasurements (i.e. are the differences large or small compared to the uncertainty)?10)Repeat the steps 2-9 for the coin “tails up”.11)Compute the difference between the measured angles in each “tails up” trial to theaverage of the “heads up” trail. Quantitatively compare this to the average uncertainty ofthe “heads up” trial.12)Based on your measurements and your answer from 11) would you say that the angle depends on which side of the coin is facing up? Explain.13)Listat least 2 thingsthatcontributed to the uncertainty of your measurements and explain how you might improve them.14)List at least 2 things that might have contributed to any inaccuracy of your measurements and explain how you might improve