Physics: Principles and Problems
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ACT/PSAE practice
Intro to acceleration
– What does it mean in common language?
– What does it mean to a physicist? (That’s you!)
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First equation of acceleration
– A = v/t
– Standard unit for acceleration: m/s^2
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Example Problem
HW: Acceleration WS #1
– Be sure to convert km/h to m/s!
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What is acceleration? When am I accelerating?
Is acceleration a scalar or vector?
How do I solve a physics problem involving
Acceleration?
What does a position-time graph of
acceleration look like?
What are velocity-time graphs, and how can I
find distance travelled and instantaneous
acceleration
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What does it mean to you in common
conversation?
What is the book’s definition?
“Deceleration” is just acceleration in a
negative direction
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______ is riding their bike to school. They
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1. You run the 100 meter dash with an
average velocity of 8 m/s. How long does it
take you to finish?
2. Make a position-time graph of the
following motion diagram:
(Line shows meters)
(Hint: how long did it take to go 10 meters?)
3. If your car can accelerate from rest to 20
m/s in 4 seconds, what is its acceleration?
When you fall, do you fall at a constant rate or
accelerated rate? How do you know? Use
complete sentences (UCS).
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Is acceleration a scalar or vector? How do you
know? Use complete sentences (UCS).
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Collect Reaction Time Lab
Bellringer
Introduce Acceleration Equation #2:
◦ THE MONSTER!
◦ df = ½ a* t^2 + Vyi * t + di
◦ Example Problem
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Acceleration WS #2
◦ Due Wednesday
 EQ: How does acceleration affect distance travelled?
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Already know: Acceleration = (Vf – Vi) / t
How do we find displacement?
Df = ½ a * (t)^2 + Vi * t + Di
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Df =
a=
t=
Vi =
Di =
What kind of equation/relationship/graph is
this?
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If your car can accelerate at 5 m/s2, how long
will it take the car to accelerate from 10 m/s
to 25 m/s?
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Bellringer
Graphing Assignment
Acceleration WS 2 pushed back to Thursday
(for this class only)
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Draw a position time graph of the following:
◦ 1. An
◦ 2. An
other
◦ 3. An
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object travelling at a constant velocity
object that is not moving (start it at a position
than zero so we can see the line)
object travelling that changes its velocity.
Make sure to label your axes!
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Bellringer
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Average Velocity WS corrections [10 min]
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Reading Guide 3.1-3.2 [10 min]
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Finish Acceleration ws 2
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Collect Acceleration WS 2
Lab: Speed Freaks 2.0
◦ Go to the FOOTBALL FIELD!
 Essential
Questions:
◦ What does acceleration look and feel like?
◦ How do we calculate speed and acceleration?
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Introduce ‘g’
◦ -9.8 m/s^2
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Hang Time Lab
◦ Finish by tomorrow first thing!
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Essential Questions:
◦ Does gravity pull things down at a constant velocity
or accelerated? At what rate?
◦ How does gravity affect how I jump?
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Collect Ch 2.2 Reading Guide
Learn Breaking Distance Equation
Problem Reading Trainer
Accelerated Problem Poster Project
◦ Buy a poster this weekend. In fact, buy 5 posters.
◦ Show Examples
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Project: Make a parachute for an Egg
◦ Make it out of anything.
 Paper / plastic bags, newspaper
 String, tape, glue, staples
 Empty cartons for basket
◦ Project Rubric Next Week
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This equation is used when time is not
involved (not given or asked for)
Vf^2 = Vi^2 + 2 * a * d
Notice: no time!
______ is about to crash into _______. Their
velocity is ________. If the cars are ______m
apart, what acceleration do they need to have
to avoid a crash?
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Velocity = disp. / time
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A = Vf – Vi / t
◦ Vavg = Dd / Dt
◦ Constant Velocity means
no acceleration.. Use this
forumla!
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Df = ½a*t2 + Vi*t + di
Standard unit for
velocity is m/s
◦ Shortcut: t = sqrt(2*d/a)
◦ Only to be used when
falling and Vi = 0.
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Vf^2 = Vi^2 + 2 * a * d
Acceleration due to
gravity : g = -9.8 m/s2
◦ “fall, thrown, drop? Use g”
CHAPTER 2
CHAPTER 3
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Collect Corrected Work
ACT/PSAE Practice
Distribute Problem Reading Trainer
Essential Questions:
What are the common elements to solving a
physics problem?
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A ball rolls horizontally at 6 m/s. How long
will it take the ball to cover 30 meters?
A ball rolls off of a table. It falls for 1 second
before hitting the ground. How tall is the
table?
Make a p-t graph of someone walking
forward for 2 seconds, stopping for 2 sec,
and backwards for 2 sec.
 Extra credit: make a velocity-time graph of this too!
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A football is thrown
down field. It is caught
at the same height that
it was thrown. It is
thrown at 20 m/s.
How fast is it going
when it is caught?
Write in 1-3 complete
sentences HOW DO
YOU KNOW?!?
Bellringer
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Bellringer
Interim Assessment #1
◦ Do not write on the test
◦ You must bubble in Name
and ID
◦ You MUST WRITE at the
top: “Hedden Period _”
◦ Pass back work
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Go over the toughest
assignment
Agenda
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Used for Right
triangles only
Involves Sine, Cosine,
and Tangent
Can be used to find an
angle or side of a
triangle by using two
other parts of the
triangle.
Pythagorean Theorem
a2 + b2 = c2
SOH CAH TOA
𝑜𝑝𝑝
𝑆𝑖𝑛 𝜃 =
ℎ𝑦𝑝
𝐶𝑜𝑠 𝜃 =
𝑎𝑑𝑗
ℎ𝑦𝑝
𝑜𝑝𝑝
𝑇𝑎𝑛 𝜃 =
𝑎𝑑𝑗