Graphing Motion: the 100m Sprint.
Name: __________________________________
Aim: To record information on displacement and time for a sprinter running a 100m sprint.
Equipment: Stopwatch, trundle wheel, chalk
Method: Set up 10-metre intervals on a 100m running track.
When the starter says “go”, the timers start timing and the sprinter run towards the finish.
The timers stop their stopwatches when the sprinter runs past them.
Collect data for at least three sprinters. (If a bike is available you might like to collect data for a 100m bike sprint as well.)
A
B
C
D
E
F
G
H
Eg. If
Split Times (s)
Displacement
Times for each
Average
Mid10m: 2.36s
(m)
ten-meter interval
Velocity
point
20m: 4.24s
(s)
during each Time (s)
Column F:
(from
for Subject _____ 10m interval
column
B
or
Time For Each 10m
(1, 2, or 3)
(m/s)
C or D)
Interval = 4.24s –
Subject 1
Subject 2
Subject 3
v=x/t (ie.
(see note on
10m/Column F)
2.36s = 1.88s
right)
(it took 1.88s to run
0
0
0
0
0
0
from the 10m mark
10
0 - 10m
to the 20m mark)
20
10 - 20m
30
20 - 30m
Column G:
40
30 - 40m
Average velocity in
50
40 - 50m
each 10m interval,
60
50 -60m
v = x/t
70
60 - 70m
v = 10m/1.88s
80
70 - 80m
v = 5.3m/s
90
80 - 90m
(the runner’s average
100
90 - 100m
velocity between the
10m mark and the
Draw
20m mark was
 Displacement vs Time graphs (Column A vs Columns B, C, and D) for your three
5.3m/s)
subjects on one set of axes with displacement on the y-axis and time on the x-axis.
Draw a “line-of-best-fit”.
Column H:
 a Velocity vs Time graph (Column G vs Column H) for one of the subjects with
Mid-point time
velocity on the y-axis and time on the x-axis. (see the Column H note in the text box.)
= (2.36s + 4.24s)/2 =
Draw a line-of-best-fit.
3.3s
The average velocity
Q1. How far did each subject run
Q5. How far did each subject run
in each time interval
in 1 second?
in the first second?
is fairly close to the
(i)
_______________
(i)
_______________
actual velocity half
(ii)
_______________
(ii)
_______________
way in time between
(iii)
_______________
(iii)
_______________
the start of the
Q2. How far did each subject run
Q6. How far did each subject run
interval and the end
in 2 seconds?
in the second second?
of the time interval
(i)
_______________
(i)
_______________
(the mid-point time).
(ii)
_______________
(ii)
_______________
When we draw a
(iii)
_______________
(iii)
_______________
velocity vs time
Q3. How far did each subject run
Q7. How far did each subject run
graph we will assume
in 3 seconds?
in the third second?
that the average
(i)
_______________
(i)
_______________
velocity of 5.3m/s
(ii)
_______________
(ii)
_______________
was the actual (or
(iii)
_______________
(iii)
_______________
“instantaneous”)
velocity at the 3.3s
Q4. How much time did it take for
Q8. What do you notice about the
mark. This is only an
each subject to run 35 metres?
distances in questions 5, 6 and 7?
approximation, but
(i)
_______________
Q9. How can you judge a runner’s
it’s the best we can
(ii)
_______________
velocity from a Displacement vs
do with the available
(iii)
_______________
Time graph?
data.
Q10. How did the runners’
(Note: the answers to Qs 5-7 below are not
necessarily the same as the answers to Qs
1-3)
velocities change during their
sprints?