Set up a modified Atwood's machine, with at least 20 g of mass hanging from a string that goes over a pulley, with the cart attached to the other side of the string. Turn a cart over, and test the wheels by spinning them (if they don't freely spin, or noticeably slow down right away, the axles will need to be replaced).Tasks (Record your lab partners' names on your worksheet for tasks 1-2, to be turned in at the end of today's lab for randomly selected grading for your group.) Students build upon previous knowledge of graphing and curve-fitting software, and best practices for data collection and graphical analysis.
#How to save graphs from pasco capstone how to#
Students learn how to account for measurement uncertainties, and to display these using error bars on graphs. Students learn how to use ultrasound sensors to track the motion of objects. Students work in (self-assigned?) groups to model the behavior of a two-body system (modified Atwood's machine). Data with measurement uncertainties can represented graphically using error bars. Ultrasound sensors can be used to track the motion of objects. "750 Interface" box, power and USB cablesĪ system of objects subject to an external net force along a fixed direction will accelerate along that direction (Newton's second law). Table clamp, right-angle clamp, rods (for pulley)Ĭollision track, cart, "cargo blocks," pulley, string Other Reasons Why Things Go Wrong!, Price/Stern/Sloan (1977), p. "Vesilind's Laws of Experimentation," cited by Arthur Bloch, Murphy's Law and "If a straight line fit is required, obtain only two data points." "If reproducibility may be a problem, conduct the test only once."Ģ. DON'T let it fly off or crash into anything. Second, gently push the cart down the ramp. We will consider three cases for the sloped track: First, allow the cart to roll (without an initial push) down the ramp. Measure the angle using a protractor or calculate it by measuring the two legs of the triangle and using the inverse sine. Place a small block under one end of the track, so that the track is now tilted at a small angle with the sensor at the top of the incline. (Although you should not include the acceleration versus time graph, if you view it in Capstone, you should notice that it is very noisy.) Subsection 3.2.2 Cart and Sloped Track ¶ You should also print out (in landscape mode) the position versus time graph and the velocity versus time graph. Interpret the coefficients (slope and intercept) by noting their units, values, and uncertainties. Fit each with a trendline and display the equation of the trendline on the screen. On Capstone, you should have two curves of velocity versus time. For each case, start the sonic ranger and then bump the cart firmly, but not violently(!). The two speeds should be, to the best of your ability, about the same. These trial-runs should help you take your actual data more efficiently and effectively.įor your lab report, take two sets of data: a constant velocity towards the ranger and a constant velocity away from the ranger. Push a cart forwards and backwards to see what this looks like on the graph.
Make a graph of a slow cart moving forwards and a fast cart moving backwards to see what the difference looks like on a graph. You should be able to indicate how you would see each effect in the graphs of the motion.īefore taking data for the lab, develop your familiarity with the equipment by playing with making velocity versus time measurements. If the track has friction with no tilt then describe the motion in each direction using the phrases “speeding up” or “slowing down”. If the track is tilted with no friction then describe the motion in each direction using the phrases “speeding up” or “slowing down”. (This is explained in Appendix C.) Checkpoint 3.1. Capstone, via the sonic ranger, can measure the position and velocity of the cart as a function of time.
(You might need to use the “sail” for the sensor to see the cart.) Place the sensor about 20 cm from the end of the track, because this is the minimum distance detected by the sensor.
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