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espinoza (mee536) – HW2 – ditmire – (58216)
1
This printout should have 25 questions.
Multiplechoice questions may continue on
the next column or page – fnd all choices
beFore answering.
001
(part 1 oF 3) 10.0 points
The scale on the horizontal axis is 2 s per divi
sion and on the vertical axis 5 m per division.
0
1
2
3
4
5
6
0
1
2
3
4
5
6
7
8
9
time (
×
2 s)
position (
×
5 m)
What is the initial position?
Correct answer: 0.
Explanation:
At time
t
= 0, the position is 0.
002
(part 2 oF 3) 10.0 points
What is the fnal position?
Correct answer: 20 m.
Explanation:
The fnal position is read From the graph
and is 4 times the vertical scale Factor (5 m).
p
f
= 4 (5 m) =
160 m
.
003
(part 3 oF 3) 10.0 points
What velocity is represented by the graph?
Correct answer: 1
.
25 m
/
s.
Explanation:
The velocity is the slope oF the
position
vs
time
graph, so
v
=
Δ
p
Δ
t
=
4 (5 m)
8 (2 s)
=
1
.
25 m
/
s
.
004
(part 1 oF 3) 10.0 points
Consider the plot below describing motion
along a straight line with an initial position oF
x
0
= 10 m.

1
0
1
2
3
4
5
6
7
1
2
3
4
5
6
7
8
9
b
b
b
b
b
time (s)
velocity (m/s)
What is the position at 2 seconds?
Correct answer: 13 m.
Explanation:
The initial position given in the problem is
10 m.
b
b
b
b
b
b
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7

1
time (s)
The position at 2 seconds is 10 meters plus
the area oF the triangle (shaded in the above
plot)
x
= 10 m +
1
2
(2 s

0 s)
×
(3 m
/
s

0 m
/
s)
=
13 m
;
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View Full Document espinoza (mee536) – HW2 – ditmire – (58216)
2
however, it can also be calculated:
x
=
x
i
+
v
i
(
t
f

t
i
) +
1
2
(
t
f

t
i
)
2
= (10 m) + (0 m
/
s) (2 s

0 s)
+
1
2
(1
.
5 m
/
s
2
) (2 s

0 s)
2
= 13 m
.
005
(part 2 of 3) 10.0 points
What is the position at 6 seconds?
Correct answer: 33 m.
Explanation:
The position is 13 m plus the area of the
trapezoid from 2 s to 6 s
x
= 13 m +
1
2
(6 s

2 s)
×
(7 m
/
s + 3 m
/
s)
=
33 m
;
however, it can also be calculated:
x
=
x
i
+
v
i
(
t
f

t
i
) +
1
2
(
t
f

t
i
)
2
= (13 m) + (3 m
/
s) (6 s

2 s)
+
1
2
(1 m
/
s
2
) (6 s

2 s)
2
= 33 m
.
006
(part 3 of 3) 10.0 points
What is the position at 8 seconds?
Correct answer: 32
.
3333 m.
Explanation:
The position is 33 m minus the area of the
triangle from 6 s to 8 s
x
= (33 m) +
1
2
(8 s

6 s)
×
(

0
.
666667 m
/
s

0 m
/
s)
=
32
.
3333 m
;
however, it can also be calculated
x
=
x
i
+
v
i
(
t
f

t
i
) +
1
2
(
t
f

t
i
)
2
= 33 m + (0 m
/
s) (8 s

6 s)
+
1
2
(

0
.
333333 m
/
s
2
) (8 s

6 s)
2
= 32
.
3333 m
.
007
(part 1 of 4) 10.0 points
Consider the plot below describing the accel
eration of a particle along a straight line with
an initial position of 3 m and an initial veloc
ity of 0 m
/
s.

1
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
time (s)
acceleration (m/s
2
)
What is the velocity at 1 s?
Correct answer: 6 m
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This note was uploaded on 09/19/2010 for the course PHY 303K taught by Professor Turner during the Spring '08 term at University of Texas at Austin.
 Spring '08
 Turner
 Physics

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