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Kinematics - One Dimension
Introduction
| Mechanics |
Study of the motion of objects, and related
concepts of force and energy. It includes the areas of kinematics
and dynamics.
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| Kinematics |
Description of how objects move.
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| Dynamics |
Why objects move as the do.
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| Translational motion |
Nonrotational motion
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| Rectilinear motion |
Motion along a straight-line path. |
Converting Units
Change fraction units into equalities example 120 km/h => 120 km = 1 h
This is an extremely important
concept. Any fractional unit can be written as an
equality. Two linked measurements can also be written as an equality
Example: if a football player runs 50.0 meters in 4.9 seconds
=> 50.0 m = 4.9 s
Analysis and Conversion of units is an extremely important step in Physics
Problems.
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Converting Units Process
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| 1. |
Write all equalities that are likely to be
used. Examples:
1 km = 1000 m
1 h = 60 min = 3600 s
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| 2. |
Set Goal based on the desired units for the
answer.
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| 3. |
Get all parts of the goal in the proper
location, numerator and denominator.
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| 4. |
Cancel all remaining unnecessary units. |
Convert 120 km/h into m/s.
1 km = 1000 m
1 h = 3600 s
120 km = 1 h
m
Goal is ------
s
1000
m 1
h 120 km
----------- x ------------ x --------------- = 33.3 m/s
1 km 3600
s 1 h |
1. Write
equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
Convert 15.3 cm/s into m/min
1 m = 100 cm
1 min = 60 s
15.3 cm = 1 s
m
Goal is ------
min
1
m
60 s 15.3 cm
----------- x ---------- x ------------- = 9.18 m/min
100 cm 1
min 1 s |
1. Write
equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
Convert 43.1 cm/s into km/h
1 km = 10000 cm
1 h = 3600 s
43.1 cm = 1 s
km
Goal is -------
h
1
km 3600
s 43.1 cm
-------------- x ------------ x ------------- = 1.55 km/h
10000 cm 1
h
1 s |
1. Write
equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
Table of Contents
Conversion
Problems
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1. |
5.33 m/min = _____________ cm/s |
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2. |
150. km/h =
_____________ m/min |
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3. |
8.75 m/s =
______________ km/h |
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4. |
285 cm/s =
______________ km/h |
Table of Contents
Conversion
Answers
| 1. |
5.33 m/min = _____________
cm/s
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|
1 m
= 100 cm
1 min = 60 s
5.33 m = 1 min
cm
Goal is --------
s
100 cm 1
min 5.33 m
---------- x ---------- x ----------- = 8.33 cm/s
1 m 60
s 1 min |
1.
Write equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
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|
|
| 2. |
150. km/h = _____________
m/min
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|
|
1 h
= 60 min
1 km = 1000 m
150. km = 1 h
m
Goal is ------
min
1000
m 1
h 150. km
----------- x ----------- x ------------- = 2.50 x 10 3 m/min
1 km 60
min 1 h |
1.
Write equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
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|
|
| 3. |
8.75 m/s =
______________ km/h
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|
|
1 h
= 3600 s
1 km = 1000 m
8.75 m = 1 s
km
Goal is -------
h
1
km 3600
s 8.75 m
---------- x ----------- x ------------ = 31.5 km/h
1000 m 1
h
1 s |
1.
Write equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
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|
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| 4. |
285 cm/s =
______________ km/h
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|
|
1km
= 100000 cm
1 h = 3600 s
285 cm = 1 s
km
Goal is -------
h
1
km
3600 s 285 cm
---------------- x ------------ x ------------ = 10.3 km/h
100000 cm 1
h
1 s |
1.
Write equalities
2. Set Goal
3. Get m in numerator and s in
denominator
4. Cancel km and h |
Table of Contents
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