Name: ___________________________________________________ Teacher’s initials: ____
Using Tickertape to get the speed of your constant velocity buggy
(pictures and text from http://www.physicsclassroom.com/class/1dkin/u1l2b.cfm)
Ticker Tape Diagrams
A common way of analyzing the motion of objects in physics labs is to perform a ticker tape analysis. A long tape is
attached to a moving object and threaded through a device that places a tick upon the tape at regular intervals of time say every 0.10 second. As the object moves, it drags the tape through the "ticker," thus leaving a trail of dots. The trail of
dots provides a history of the object's motion and therefore a representation of the object's motion.
The distance between dots on a ticker tape represents the object's position change during that time interval. A large
distance between dots indicates that the object was moving fast during that time interval. A small distance between dots
means the object was moving slow during that time interval. Ticker tapes for a fast- and slow-moving object are depicted
below.
The analysis of a ticker tape diagram will also reveal if the object is moving with a constant velocity or accelerating. A
changing distance between dots indicates a changing velocity and thus an acceleration. A constant distance between dots
represents a constant velocity and therefore no acceleration. Ticker tapes for objects moving with a constant velocity and
with an accelerated motion are shown below.
And so ticker tape diagrams provide one more means of representing various features of the motion of objects.
Using a tickertape timer to get the speed of the constant speed buggy, p. 1
Let’s make a tickertape for our little constant speed buggy car and then let’s use our dots to create a data table and
finally, a position-time graph (also called a distance-time graph).
Things you will need
 Constant speed buggy
 Tickertape machine
 Meterstick or ruler
 Masking tape
 Extension cord
(1) Create a ticker tape of your buggy
a. Plug in your tickertape timer and set it on a flat surface. Use your extension cord if needed.
b. Tear off about 1 meter of tickertape
c. Feed the tickertape curved side down into your machine
d. Tape one end on the back side of your car with masking tape.
e. Turn on your tickertape machine and then your buggy and allow the buggy to move forward. The tape
should follow the buggy through the tickertape machine.
f. When the tape has all been fed through the machine, turn off the tickertape machine and the buggy.
g. Make sure you have dots on the tickertape and label the start of the tape.
(2) Use the tickertape to get your data, make sure to use the part of the tape after your car gets up to speed.
a. Count about 10 points from the start and label this point ‘0’. Then label 10 more points ‘1’ through
’10.’
b. Use your ruler or meterstick to measure the distance from point 0 to 1. Measure in centimeters.
Make sure you know how to do this; if not ask. Put this distance on your data table.
c. Measure 0-2, 0-3, 0-4, etc. the same way. Place these distances on your data table, too.
Tickertape
point
0
0-1
0-2
0-3
0-4
0-5
0-6
Time (sec)
0
0.1
0.2
0.3
0.4
0.5
0.6
Distance
(cm)
0
Tickertape
Point
0-7
0-8
0-9
0-10
Time (sec)
Distance
(cm)
0.7
0.8
0.9
1.0
3. Let’s make our position-time (also called a distance-time graph).
a. On the next page, there is a blank graph. You will graph the time (x data) with your distance (y
data). Put data points on your graph given your coordinate points: (average time, distance)
Using a tickertape timer to get the speed of the constant speed buggy, p. 2
b. Your graph should now show some points that trend like a line. Put your ruler in the middle of the points so
it ‘follows’ the data points. With your ruler, draw your line.
c. Get the slope of your line. Choose two coordinate points on the line. This represents your speed of your
buggy. Remember that slope is
.
If you are having trouble with the slope or are not sure about how to calculate it, see my example on the next
page. The example comes from the previous experiment using the stopwatch and metersticks but it still offers
an example. Your points will be different.
Step 9: Your buggy’s speed is the slope = ____________________ cm/s
Step 10: It’s always good to note possible errors or issues that came up in an experiment. Discuss in several
sentences problems or places in the experiment where errors caused or could cause your data to give you an
incorrect speed:
Using a tickertape timer to get the speed of the constant speed buggy, p. 3
Example of finding slope:
Using a tickertape timer to get the speed of the constant speed buggy, p. 4