Name: _________________________________
Period: ____
STEM Motion Lab
Part 1 :
Create a hypothesis, figure out the time between dots at constant velocity (see Part 1 sheet)
PURPOSE: To observe the motion of a toy car, create and analyze position versus time and velocity versus
time graphs of this motion.
HYPOTHESIS: You need to type what you think will happen in terms of the motion of the car, as well as
what your position and time graph and velocity and time graph will look like when completed. Create a
prediction based off your hypothesis, and write this in IF AND THEN format.
My hypothesis:
Prediction:
MATERIALS:
PROCEDURE:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Ticker tape
Meter stick
Long Flat Surface
Spark Timer
Pull-Back Toy car
Masking tape
****DO NOT USE TICKER TAPE WITH TIMER YET!!!****
TRIAL RUN WITH TIMER OFF:
Set up a horizontal runway. Make sure the car has enough space to stop. Check with teacher
before doing any experiment!!!
Thread the ticker tape through the timer (curved downward). Make sure there are no tangles, etc
that may prevent the car from running smoothly.
Attach the long length of ticker tape to the back of a toy car using the masking tape. Make sure
it is long enough to record the entire speed!
DON’T TURN ON THE SPARK TIMER YET. Set up the ticker timer by plugging it in. Choose
the following starting Hz for your spark timer  10 Hz
Note the teacher’s instructions about the spark timing before you start.
Note the distance you want to pull the car back, then pull it back positioning the car close to the
spark timer pointed straight down the “runway”.
Let go of your car with the timer OFF, and see how the tape runs through the timer. When the
car has stopped, the end of the tape should end up either still in the timer or just out of the
timer.
Adjust accordingly. Repeat with timer off as necessary.
EXPERIMENTAL TEST RUN:
Setup by Repeating steps 1, 2, and 3.
Make sure your car is at the correct pull back distance (control variable).
Check the starting Hz for your spark timer and record 10 Hz
Note the teacher’s instructions about timing before you start.
Start the spark timer. When your team is ready, release the toy car.
When the toy car has stopped, stop the spark timer also.
Write your name and class period on the back of your ticker tape, and move forward on the lab
using the ticker tape data. Keep these in the classroom – do not lose.
Part 2 Analyzing Data
DATA/RESULTS – Position (x)
1.
Use the data table with the following headings. Make sure to understand/read carefully what each
column asks for data input… collaborate with your group.
2. If you’re at 10Hz, on your length of ticker tape, count and mark off every 10th dot.
3. The ticker timer makes 10 dots per second. Therefore, the time recorded in the data table should
be tenths of a second (0.0s = dot #1, 0.1s = dot #2, 0.2s = dot #3, etc dot 10 should be at 1s of
time).
4. Figure out your UNITS of measurement and look at the diagram below:
Example:
Clock
Reading
Time (t)
0.00
0.10
0.20
0.30
…
Position (x)
0.00 (d0)
2.54 (d1)
6.73 (d2)
10.28 (d3)
…
5. Using a meter stick, (if you used 10Hz) measure the length from
the first dot to the 10 dot. Record the length in the position column of your table.
6. Then measure the length from the first dot to the 10th dot. Record. Repeat the process for
every 10th dot, always measuring from the first dot. This is recorded in the position column of
your table.
th
Part 3 Creating Graphs
Using Google Sheets
7. Create a position-time graph from the data table. Label all axes with physical quantities and
units.
8. From the data table, create a velocity-time graph. (Calculate change in position over change in
time = velocity).
9. Make sure all graphs are clearly labeled, show appropriate scales on the axes, and have titles.
Connect the points with an appropriate line of best fit (straight or curved). The line of best fit
can be created using Excel -and it gives you a formula too!
Background Info:
•
Use instantaneous velocities (see reading below for description).
--------------------------------------------------------------------------------------------------------READ THE FOLLOWING:
There is a special thing called instantaneous velocity. That's the velocity at a split
second in time. Above, we were talking about your speed and direction over a long
period of time. Why would you need to measure a velocity at one moment? Think
about the moment you drove over the manhole. It's important to know if you were
going 1 km/hr when you drove over the manhole, or 60 km/hr. It wouldn't help you to
know that your average speed was 30 km/hr.
The term "instantaneous" refers to something physicists call a limit. Scientists "limit"
the amount of time they do the measurement. When the "limit" moves to zero, that limit is one tiny
moment in time. A physicist would measure your velocity as the "limit for a period of time", zero, to
get the instantaneous velocity.
The Total Distance Measured/Time (Dot Time Period from Part I) = Average
Velocity
Changing Your Velocity (acceleration):
When velocity is changing, the word acceleration is used.
Acceleration is also a vector. You speed up if the acceleration
and velocity point in the same direction. You slow down (also
referred to as decelerating) if the acceleration and velocity point
in opposite directions. When you accelerate or decelerate, you
change your velocity by a specific amount over a specific amount
of time (change in velocity over change in time = acceleration).
Just as with velocity, there is something called instantaneous
acceleration. Instantaneous means scientists measure your
acceleration for a specific moment of time. That way they can
say he was accelerating at exactly this amount at this point during his trip.
Part 4 Analyzing Graphs
ANALYSIS - to answer along with your graphs. Remember these should be answered using complete
sentences.
POSITION- TIME GRAPH:
1. Describe the motion of the car in terms of position.
2. What does your position graph explain about your car over time?
3. Label any position changes that were constant for more than .1s on your graph (use another
color pen or highlighter and include a key)
4. What is the relationship between the steepness of the slope of the graph and the position of
the movement?
5. Was there a point when did the car change positions the most? If so, where? If not, why?
VELOCITY- TIME GRAPH:
6. Describe the motion of the car in terms of velocity.
7. According to the velocity-time graph, are there any segments when the car was undergoing
uniform acceleration (constant)? How can you tell?
8. Where was the car’s velocity the greatest (Give specific points and label this on your graph –
use another pen or colors & add a key).
9. What is the relationship between the steepness of the slope of the graph and the velocity of
the movement?
10. What is the average velocity of the car for the entire journey? How did you figure this out?
11. Were you surprised by any of the data on either graph? Why or why not?
12. Do you expect that other groups had similar results?
Laboratory Checklist
This lab should be conducted with your group of about four students for part 1, all other
parts should be completed with just your partner.
You will complete the answers to this lab in a Google document (take a picture of the
handwritten data sheet from Part 2 and upload it). This document will be titled with you
and your partners name “_______________ and _______________ STEM Motion Lab”
Place this lab in your science period ___ folder.
All parts and questions associated with each part. The different parts will need to be
labeled appropriately. Part 1…… Part2……
Position-time & velocity-time graphs will be created in Google sheets and copy and pasted
into your Google doc.