Kinematic Equations - Plain Local Schools

taupeselectionMechanics

Nov 14, 2013 (3 years and 6 months ago)

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Kinematics


Kinematic Equations

http://
www.aplusphysics.com
/courses/honors/kinematics/
honors_kinematics.html

Unit #2 Kinematics


Objectives and Learning Targets


Use kinematic equations to solve problems for
objects moving at a constant acceleration in a
straight line and in free fall.


Resolve a vector into perpendicular components:
both graphically and algebraically.

Unit #2 Kinematics


Kinematic Equations


These equations can help you solve for key variables
describing the motion of an object when you have a
constant acceleration
. Once you
know

the value of
any three variables
, you can use the kinematic
equations to solve for the other two!

Unit #2 Kinematics


Key Kinematics Variables


Variable

Meaning


v
0

Initial velocity


v

Final velocity


Δx

Displacement


a

Acceleration


t

Time elapsed


Problem Solving Strategy


In using these equations to solve motion problems, it’s important to take care in
setting up your analysis before diving in to a solution. Key steps to solving kinematics
problems include:


1. Labeling
your analysis for horizontal (x
-
axis) or vertical (y
-
axis) motion.


2. Choosing
and indicating a positive direction (typically the direction of





initial
motion).


3. Creating
a motion analysis table (v
0
, v,
Δx
, a, t). Note that
Δx

is a






change
in position, or displacement, and can be re
-
written as x
-
x
0
.


4. Using
what you know about the problem to fill in your “givens” in
the table
.


5. Once
you know three items in the table, use kinematic equations to




solve
for any unknowns.


6. Verify
that your solution makes sense
.



(Note: these equations work for vertical and horizontal motion)

Unit #2 Kinematics


Sample Problem #1


Horizontal Motion

Unit #2 Kinematics


Sample Problem #1


Horizontal Motion

Unit #2 Kinematics


Sample Problem
#2


Vertical
Motion

Unit #2 Kinematics


Sample Problem
#2


Vertical
Motion

Unit #2 Kinematics


Sample Problem
#3


2 Stepper

Unit #2 Kinematics


Sample Problem
#3


2 Stepper

Unit #2 Kinematics


Sample Problem
#4

Unit #2 Kinematics


Question:
An astronaut drops a hammer from 2.0 meters above the surface of the
Moon. If the acceleration due to gravity on the Moon is 1.62 meters per second
2
,
how long will it take for the hammer to fall to the Moon’s surface?



Answer
:

Create Your Own Problem


Create your own
Horizontal
M
otion
K
inematics
P
roblem
and solve it. Feel free to make it funny, but
keep it clean.


Create a second problem making it
vertical
. Solve it
also.


Trade with a neighbor and solve
each other’s
problems before turning them in.

Unit #2 Kinematics