Accelerated Motion Lab Purpose: The purpose of this lab is to investigate the nature of accelerated motion and become familiar with the Vernier Interface computer lab. Materials: computer Picket fence Vernier Lab interface ruler Procedure: (show all your work when questions are asked- each person does own work) 1. Make sure the computer is on. Da! 2. Either from the desktop, or under Programs in the start menu under Vernier Software, select Logger Pro 3.1…..not Logger Pro 2.2.1 or 2.1. 3. Under the pull down menu select File and then Open. Now chose Probes & Sensors and then Photogates. Now chose Motion Timer Picket Fence.xmbl. Three graphs and a data table ought to come up. Now we need to tell the computer the length we want to measure. Go to the pull down menu and chose Experiment and then Show Sensors (Lab Pro) and right click on the picture of the photogate under Dig/Sonic1 and chose Set Distance or Length. A small window will come up, expand the choice and chose User Defined and change the distance to the distance between the leading edges of your picket fence (see below). Press OK and close out the window d= 4. Note that the graphs will display all of the characteristics of accelerated motion. 5. Press Collect- you’re ready to go. The computer won’t start counting until the first time the beam is blocked. 6. Line up the picket fence just above the photogate and prepare to let go of it and catch it with the other hand (that would be the one not holding the photogate). Let go of the picket fence and catch it. See if you collected 10+ points of data (time) from the table, if so, click Stop. 7. Copy the accelerations and find the average acceleration. Click on the acceleration vs All Accel time graph and press the Stats button and copy the Mean value. 1 Acceleration Ave. _________ Mean (stats) ______________ 2 3 8. Click on the X=? Place the on different parts of the slope and 4 the value of the velocity and time that those points. 5 9. Click on the M= button and place your cursor at different 6 positions along the slope and note the tangent value at that 7 point. This tangent is the instantaneous acceleration at that 8 point. 11. Now click on the Velocity vs. Time graph (so it’s highlighted) and press the R= button and record the slope of the velocity/time graph. How does this value compare with the average acceleration you calculated in #7? #7__________ R= __________ 12. Now click on the button and note the integral value for the vel. Vs. time graph. This is the rise x run, or, velocity x time, which is the distance covered during the experiment. Note the times over which the distance was measured and see if it is the same for the distance actually covered during that time (analyze from data table) Compare this distance to the distance from the leading edge of the first opaque bar the leading edge of the last.comp. integral value_________ measured dist. _________ 13. Highlight the Dist. vs. Time graph and press the f/x button. The shape of this graph is a parabola so the relationship between dist. and time is quadratic. Check Quadratic an then try fit 14. What is the Ea and Er values of the acceleration due to gravity you measured?