Paper Trail Motion
Pre-Lab Questions:
1. During Part 1, Calibration, what type of motion is occurring? (no motion, constant velocity, acceleration)?
2. What should the dots on the paper trail look like during Part 1, Calibration (evenly spaced, getting closer together, …)?
3. During Part 2, Data Acquisition, what type of motion is occurring (no motion, constant velocity, acceleration)?
4. What should the dots look like during Part 2, Data Acquisition (evenly spaced, getting closer together, …)?
Procedure:
Preparation - Creating the paper trail:
· Cut several strips of binder paper about 1 inch thick.
· Tape the ends of the paper together to create a paper trail as long as the ramp you will be using in Part 2.
· Repeat as needed
Part 1 - Calibration – Finding the Period (Time between dots)
1. Choose a person to be the Marker. The Marker will need to be able to keep the beat of the metronome at the front of the class.
2. Leave a few inches from the end of the paper and label that the start.
3. The Marker will write dots on the paper trail in time with the metronome as someone else pulls the tape at a reasonable constant speed and record the time from the stopwatch. (The time is from when you begin to pull until the tape leaves the Marker.)
4. Record the time in the table below and count all of the dots from where the stopwatch started to where the stopwatch stopped.
Data Table #1
Trial # / Number of Dots / Time(sec) / Period
(sec/dot)
1
2
3
Average: / XXXXXX / XXXXXX
______Your Average Period (T) à The Time between EACH dot.
***This AVERAGE PERIOD will act as your timer in Part II
Part 2 - Data Acquisition – Cart Acceleration
1. Put the stopwatch away; it is no longer needed.
2. Tape your Paper Trail to the back of the cart. Set the cart on top of the ramp.
3. When the Marker is ready, release the cart.
4. As the cart rolls down the ramp, the Marker should be creating dots on the Paper Trail in time with the metronome (just like before).
5. Someone else needs to catch the cart at the end of the ramp.
6. The dots should be spaced farther and farther apart.
Data Analysis – Reading the Motion Maps/Paper Trails
Distance Data – Data Table 2
1. Use the tape you made from rolling the cart down the ramp.
2. Number the dots. The starting line is your “0” mark or “Starting Point”. The next dot is #1, the next dot is #2 and so on until you have labeled the whole trail.
3. Measure the distance (in cm) from the “Starting point” to Dot #1 and record the distance in Data Table 2 under the column labeled “Total Distance”.
4. Now measure the distance between the “Starting Point” to Dot #2 and record in the table. Repeat this with the “Starting Point” to Dot #3 and so on until you have recorded all the Total Distances for all the dots.
5. The Total Time is the time elapsed from the beginning to that dot. (Dot # times Average Period)
Velocity Data – Data Table 3
6. Record the distance (in cm) from the “Starting Point” to Dot #1 and record in Table 3 under “Dot Distance”
7. Measure the distance between Dot #1 and Dot #2 and record this Dot Distance
8. Repeat with Dot #2 to Dot #3 and so on until you have measured all the dots.
9. The Dot Velocity is the distance traveled between dots (Dot Distance) divided by the time between dots (Average Period)
The Graphs for this lab must be done on Excel.
See class website for Excel Graph File & Post-Lab Questions.
Excel Graphing (At Home) – Making the Motion Graphs for Velocity and Acceleration
1. Go to Ms. Keeler’s and download the Excel file for this lab (Found under today’s date)
2. Fill in the data tables with your data.
3. Create/Locate the Total Distance vs. Time graph for the cart.
4. Create/Locate the Velocity vs. Time graph for the cart.
5. Both graphs MUST have…
a. Proper, Descriptive Title*
b. Labeled axis with units*
c. Best Fit “Shape” trendline (done for you) – Velocity vs Time ONLY
d. Equation for the plotted trendline (done for you) – Velocity vs Time ONLY
* You can do better than what is already there.
Post-Lab/Conclusion Questions:
1. What does the Paper Trail says about the cart’s (or paper’s) motion during Calibration? How do you know?
2. Describe the motion of the cart during Data Acquisition according to your Total Distance vs. Total Time graph? How can you tell from the Total Distance vs. Total Time graph?
3. For the Velocity vs. Time graph, what does the slope of the plotted line represent?
4. Why should the trend line on the Velocity vs Time graph be straight? (I am NOT looking for “trendlines are always straight” or “the trendline is an average, therefore it is always straight.”)
5. What was the acceleration of your cart according to your graph?
6. List three possible sources of unavoidable error in this lab. How could these errors be fixed?
Each Lab Report Needs:
· Title
· Pre-lab Questions (in complete sentences)
· 3 Data Tables (at least 2 made on Excel)
· Average Period (from Data Table 1) clearly marked
· 2 Excel Graphs (Use a better title & properly labeled axis)
· Post-lab Questions (in complete sentences)