lab_Accelerated_Motion_S23(2)

pdf

School

University of South Carolina *

*We aren’t endorsed by this school

Course

211

Subject

Mechanical Engineering

Date

Oct 30, 2023

Type

pdf

Pages

Uploaded by CorporalMaskKomodoDragon8

Accelerated Motion Equipment Per Group : § Motion tracks and cart § rulers, 3 stopwatches, end stop § friction block or other items to prop up end of tracks. Explorations. For all of the following activities, record in your lab notebook how your group did the measurements and what values you measured. Use Excel for making plots and extracting data. If time allows, sketch diagrams and graphs in your notebook as you proceed.

Position from Time and Quadratic Functionality. Level the track (the diagram refers to a glider and air track – your equipment may instead be a rolling cart and a plain track), and then incline it by placing a spacer under one end. Place the glider/cart at the high end of the track and note its position. One person (the starter) can hold it there while two others (the observers) sit close to the track at two positions farther down. An end stop (barrier) should be attached to the bottom end of the track to prevent the cart from becoming a projectile . Select a time-keeping device; each observer should have one. Record the time elapsed for the cart to reach different positions on the track. Repeat the procedure a few times to get an estimate of times and their uncertainty by averaging the data and taking the standard deviation . Which datum ( x or t ) seems the most accurate? Measure at different positions along the track and record the values in your notebook. In what follows, you will plot these data in order to observe the trend. Plotting on paper will be an important skill but it must be done carefully and precisely. Instead, we will use a spreadsheet because it will be precise and we can take advantage of several critical tools it provides. • Let x be the distance traveled in a certain time t . Plot your values of x and t against one another. Is x a linear function of t ? • Next, plot your values of x and t 2 (this is accomplished by squaring all the time values and plotting the distances against that variable). Is x a quadratic function of t ? Include ( x , t )=(0, 0) on each plot. • Use your x and t 2 plots to find the acceleration graphically. How is the acceleration related to the slope of your plot? Hint: use the LINEST or trendline method in Excel, as described in the excerpt from the Measurement and Uncertainty guide we asked you to read as part of the warmup. This is a critical part of the lab – be sure to ask your TAs to explain how this works if you are confused. • Notebook discussion: make an educated guess as to how the acceleration depends on the incline of the track (think about the limiting cases of a flat and a vertical track). Discussing this in your group now will be beneficial when writing your abstract later. • Uncertainty: consider how well you really know the values of x and t that were measured – think about the possible systematic issues in observation and the variability of repeated measurements. The trendline equations in the Measurement and Uncertainty guide will be used to calculate the uncertainty in the

acceleration in the next studio. Record all your results in your notebook – y ou will need them for the deliverable. Challenge Questions Not for credit but may be critical for understanding on exams or homework! 1. Why did we include the point (x, t) = (0, 0) in this activity? Come up with a similar experiment in which you would NOT include this point. Hint: what is the difference between “position,” and “distance” or “displacement?” 2. Plotting x versus t 2 is known as linearizing the plot ( x vs t is a quadratic plot, whereas x versus t 2 is a linear plot). Why is linearizing a preferred method? 3. An alternate approach is to start with a set of position and time coordinates, take the difference in times and positions to get the speeds, and then take the difference in speeds again (with times) to find the acceleration. Why is this the WRONG approach? Deliverable: Each student will be writing a laboratory Abstract that presents your acceleration result and its uncertainty, based on your Excel results (not a calculation by hand). See the Lab Reports document on the Blackboard in the General Resources for Studio folder for more information about how to write an Abstract. The due date is one week from this module. There is no deliverable from this activity to be turned in today.

lab_Accelerated_Motion_S23(2)

Related Documents

Browse Popular Homework Q&A