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OPYING PERMITTED PROVIDED
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© 1997 T
EXAS
I
NSTRUMENTS
I
NCORPORATED
G
ETTING
S
TARTED WITH
CBR
19
Activity 2—Toy car
(cont.)
linear
Explorations
➊
The values for
x
(time) in half-second intervals are in the first column in question 2.
Trace the plot and enter the corresponding
y
(distance) values in the second
column.
Note:
Include results only from the linear part of the plot. You may need to
disregard inconsistent data at the beginning of the data collection. Also, you may need
to approximate the distance (the calculator may give you distance for 0.957 and 1.01
seconds instead of exactly 1 second). Pick the closest one or take your best guess.
➋
Answer
questions 3 and 4
.
➌
Calculate the changes in distance and time between each data point to complete the
third and fourth columns. For example, to calculate
@
Distance (meters) for 1.5 seconds,
subtract Distance at 1 second from Distance at 1.5 seconds.
➍
The function illustrated by this activity is
y
=
mx
+
b
.
m
is the slope of a line. It is
calculated by:
@
distance
@
time
or
distance
2
N
distance
1
time
2
N
time
1
or
y
2
N
y
1
x
2
N
x
1
The y-intercept represents
b
.
Calculate
m
for every point.
Enter the values in the table in question 2.
➎
Answer questions 5, 6, and 7
.
Advanced Explorations
Calculating the slope of a Distance-Time plot at any time gives the object’s approximate
velocity at that time. Calculating the slope of a Velocity-Time plot gives the object’s
approximate acceleration at that time. If velocity is constant, what does acceleration equal?
Predict what the Acceleration-Time plot for this Distance-Time plot looks like.
Find the area between the Velocity-Time plot and the x-axis between any two convenient
times,
t
1
and
t
2
. This can be done by summing the areas of one or more rectangles, each
with an area given by:
area
=
v
∆
t
=
v
(
t
2
N
t
1
)
What is the physical significance of the resulting area?
