"Guide to calculate the Friction Coefficient using CBR and"
Guide to calculate the Friction Coefficient using CBR and a Graphing Calculator Make sure you have the graphing Photo 1 calculator (model TI-83 Plus), a CBR motion sensor and APPS a connecting cable. ON Oct. 5th, 2005 1 Turn the calculator ON, by pressing the button on the bottom left. You might get an Photo 2 opening screen that looks like this Then press the blue APPS button, to get this screen: Photo 3 Oct. 5th, 2005 2 Press , to get this screen: Photo 4 Press any key. You will get this screen: Photo 5 Press (Data Logger). Oct. 5th, 2005 3 Make sure that the following set-up is repeated: Photo 6 ( Use the arrow keys for selection). Click the “down” arrow until the word “GO…” is highlighted. Press (Enter) Oct. 5th, 2005 4 The following screen should appear: Photo 7 Press Press Photo 8 Oct. 5th, 2005 5 Make sure that the connecting cable is attached to the calculator from the Photo 9 CBR. Press Set the CBR down on the ground, so that it is . lying on its side. Point it in the direction you will roll your ball. Hold the ball up against the motion sensor. When you are ready to begin collecting data, have one partner press ENTER and roll your ball in a straight line away from the CBR Oct. 5th, 2005 6 It may take a few Photo 10 tries before you can get your ball to roll in a straight line in front of the sensor, but eventually, you should get a graph that looks like this: Photo 11 Oct. 5th, 2005 7 Using the left and right arrow keys , choose the first point of the graph when the curve just starts to depart from the horizontal axis. Call this point t , x t , 0 . Choose another two points on 0 o 0 the curve and call them t1 , x1 and t 2 , x2 . Both Vo and can be calculated using the relation: g x xo Vo t t o t t 2 o 2 Oct. 5th, 2005 8 Using t1 , x1 and t 2 , x2 , you will obtain two equations in two unknowns,Vo , , which can be solved by either substitution or elimination. Please refer to the handout for a detailed solution of the present problem. Oct. 5th, 2005 9