Year 9 Physics Unit 3
Methods of measuring Distance and Speed
using traditional and ICT methods.
Ticker timers
Data logging
Excel Graph Plotting
Name
…………………………………………
Tutor Group …………………………………………
The statements in the National Curriculum which ask you
to use Information and Communication Technology in
Science are as follows:
”… Developing ideas and making things happen
a)
Develop and explore information, solve problems and derive new
information for particular purposes (for example, deriving totals from
raw data, reaching conclusions by exploring information)
b)
Use ICT to measure, record, respond to and control events by
planning, testing and modifying sequences of instructions (for
example, using automatic weather stations, data logging in fieldwork
and experiments, using feedback to control devices)
c)
Use ICT to test predictions and discover patterns and relationships,
by exploring, evaluating and developing models and changing their
rules and values
d)
Recognise where groups of instructions need repeating and to
automate frequently used processes by constructing efficient
procedures that are fit for purpose (for example, templates and
macros, control procedures, formulae and calculations in
spreadsheets)
…”
You will be looking particularly at the statements underlined.
CONTENTS
Page
3
Using ticker timers to measure speed
5
Using Excel to plot graphs
6
Using data logging programs
8
Writing up your practical work
2
Measuring Velocity Using Ticker Tape
Variable Power
Supply set to
2Volts AC
In this experiment, you release the trolley so that it rolls down the ramp. A length of
ticker-tape is fixed to the trolley. The tape is pulled through the ticker timer which
prints a dot on the tape every 1/50 second or 0.02 seconds. From the spacing of the
dots you can work out how fast the trolley is moving as it moves down the ramp.
•
•
•
•
•
Set up the apparatus as shown in the diagram. Make sure you set the power
supply to 2 Volts AC.
Switch on the power supply and release the trolley.
Remove the tape and mark it into 10 dot-spaces long.
You can then cut them and stick them onto a sheet of
paper side by side or measure each length and record
them in the table below.
Calculate the speed of each section by dividing the
length by 0.2 seconds
Average speed
(cm/s)
Time
(seconds)
0
Length of
Paper
(cm)
0
Speed
(cm/s)
0
•
•
•
=
length of section (cm)
time (seconds)
You can now plot a graph of Speed of trolley against time taken.
This can be done by hand on graph paper or on an Excel spread sheet.
The following pages show you how to plot graphs on Excel.
Describe what the dots tell us about the movement of the trolley.
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3
Plotting Graphs on Excel
Start Excel
Enter your data from the ticker timer experiment into the
excel table as shown. The time should be the
accumulative time going up in 0.2 second intervals.
Add a column for the speed and use excel to
automatically calculate these using “=B3/0.2” then fill
down.
Click on the Chart Wizard icon and go through
the stages as shown below to produce a graph
of speed against time. Your preview graph should have a
In Chart Wizard select the
graph in “chart type”, and keep
to the one with points not joined
Click on “Next” then select the series by clicking on the
Icon and
highlighting the fist and third columns of your table.
The easiest way to do this is to select all three columns, then remove the
unwanted series after.
In stage 3 of the Wizard give the graph a title and label the axes.
Put gridlines, both major and minor on each axis by simply clicking on the
appropriate menu.
Remove the
tick then click “Next”
Save the graph as a
then “Finish”
Now you have finished the Chart Wizard it is a case
of double clicking on all the features on the graph, or
finding the menus, to make it look nice.
The first task is to change the “selected plot area”
colour to white in the Format menu.
Then change the shape of the points by clicking on
any point and going to Format and “Selected data
series”. From here change the foreground of the
marker to black, the background to no colour, the
style to a cross and up the size to about 8.
To change the scales select
the time axes then format this
to give a maximum that
makes the graph as big as
possible. Do the same with
the other axes.
4
Plotting Graphs on Excel
Your graph now looks more like a scientific
graph and can be easily interpreted. You can
make it look better than this but don’t waste
too much time.
The next stage is to fit a “Trendline” to these
points which is a line of best fit which Excel
will calculate for you.
So go to “Chart” then
“Add Trendline”
Select “Linear” for this graph, as it should be a
straight line
You also need to re-scale the axes at this point
and make sure the trend line goes through the
origin
Extension
Acceleration is how quickly the speed changes. We calculate it using the equation:
Acceleration
=
Fast speed – Slow speed (cm/s)
2
(cm/s )
time between sections (s)
Use you graph to find the acceleration of the trolley as it rolls down the ramp. Show your
working on the graph
Plot a Distance-time graph. To do this you will need to calculate the accumulative distance
that the trolley goes down the ramp (1st strip + 2nd strip, then 1st + 2nd + 3rd etc)
Add a forth column in your spread sheet and enter these numbers.
The graph this time should be curve, so select “Polynomial” when you come to fit the
Trendline and it should have an order of 2
When you save the new graph don’t forget to re-name the sheets so that you know what
they are (use right click)
5
Using Data Logging Programs
Set up the apparatus as shown in the diagram.
Make sure that the switch
on the base of the
sensormeter is set to 20.
card
trolley
meter rule
Interface
Computer
ramp
Box to raise
ramp
Open Datadisk Explore 32. The reading from the
meter should be displayed on the computer screen
Check the meter is working correctly by manually
moving the trolley up and down the ramp.
Use the box under the ramp to give a shallow slope
and place trolley at about 50cm from the sensor.
Click the graph
icon in the data view box.
Get ready to click the green record button.
Let the trolley go and press record button at the same
time or after (NOT BEFORE)
Click the stop button
1 metre.
after the trolley reaches
Scale your time access to display only the section that
shows the trolley’s distance changing.
Save the file to the network space and print a copy of
the graph, for each person in the group.
Close explore, open Datadisk 32, open your file and
save it as a “CSV” file which can then be used to
process the data in Excel
Re-open Explore 32 You can now use the gradient
icon
to give the velocity at each point on the
graph.
Complete the tasks on the next page.
6
1
When you have printed your graph, give it an appropriate title and
attach it to this document
2
Describe the relationship between distance and time.
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3
Use the gradient function and mark the values of speed (velocity) on
the graph at 6 points spaced evenly (avoid any bumps or dips in the
graph. Enter these with the times in the table below.
Time /
seconds
Velocity
/ m/s
4
Describe the relationship between velocity and time as the trolley
runs down the ramp.
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5
If you have time investigate how the steepness of the ramp affects
the distance-time graph. Obtain data for one or two steeper slopes
and display them on the same graph as your first data. Write a
conclusion to your results.
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7
Writing up your practical work.
Word process a two to three page account that summarises the two
practical tasks you have done.
Insert graphs and tables into the Word document and use “Draw” to
construct any diagrams.
Your account should have:
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Name
Date
Title
Aim
Labelled Diagram
Brief method
Tables of results (for ticker timer experiment only)
Graphs
Conclusions
8