WELCOME TO PHYSICS! 1) Find your name on a notecard at a seat. This is your assigned seat. 2) If you wish to be called something differently than the name given, write it underneath the name. 3) On the back of the card, number 1 to 7 downwards and Honestly answer the following. Only I will read these. 1) List a few activities or hobbies you enjoy. 2) What are your plans after high school? 3) What is the one thing about yourself that you are most proud of? 4) If When you are frustrated or feeling lost in this class, how will you resolve this? 5) How do you define success in this class? 6) Using 5 words or less, define your idea of physics. 7) Tell me something about you that I should know as a teacher.
Transcript
WELCOME TO PHYSICS!1) Find your name on a notecard at a seat. This is your
assigned seat.2) If you wish to be called something differently than the
name given, write it underneath the name.3) On the back of the card, number 1 to 7 downwards and
Honestly answer the following. Only I will read these.1) List a few activities or hobbies you enjoy.2) What are your plans after high school?3) What is the one thing about yourself that you are
most proud of?4) If When you are frustrated or feeling lost in this
class, how will you resolve this?5) How do you define success in this class?6) Using 5 words or less, define your idea of physics.7) Tell me something about you that I should know as a
teacher.
What you need for class1 notebook dedicated for this class ONLY.
Calculator-Graphing is pretty much required.
(Not required but REALLY helpful)-A set of colored pens. Recommended by last few years of students.
Internet/BCPS One access
Syllabus and MoreWhat is important….
For next class…..1) Letter signed2) Questionnaire Done3) Day 1 Assignment Finished, Checked4) Day 2 video watched/checked
What will happen today?We are going to begin our study of
physics.
1) Reviewing Dimensionality2) 3 Examples done by me3) 3 Examples done by you, confirmed by
group4) 2nd Learning/Review session of units and our
first major set of definitions5) 4 Group led problems on small boards6) Our first application activity7) Summary, link to website
My Goals For TodayAt the end of today, you should have
the tools to:
1) Be able to convert between units and be able to predict functions from the units.
2) Understand the different basic units in physics and what they mean.
3) Learn the difference between position and displacement.
Lets Start…DIMENSIONAL ANALYSISWhat is it?
Converting between units through math
Strategies1) Identify what unit you are going to
change and the result unit.2) Write it out the way I will show
you3) If you have NO idea what is being
asked, it is good to try to use dimensional analysis as a start point.
Who gives a flying fig?It is really easy to screw up the
16 miles per hour. How many feet per second is that?
23.4 feet per second
As your packet stated3 dimensionalities to start
Mass [M] in kg (m in equations)Length [L] in meters (d in equations)Time [T] in seconds (t in equations)
Using these to determine a general approach is a KILLER IDEA
Example TwoA car driven by a distracted panda goes from
speed vi to vf over some distance d. Which of the following represents the force of the car during that distance? (Assume force is in kg.m/s2)
A) mp (vf2 – vi
2) 2
B) mp (vf2 – vi
2) 2d
A) mp (vf – vi) 2
A) mp (vf – vi) 2d
B…this is a released question
Example 3 VOTINGYour tank holds around 18.6 gallons
of gas, but shows it to be exactly ¼ full. The next gas station is 73 miles away. You drive so your car gets 14mpg for the first ½ of that distance. What mpg do you need for the 2nd half to just make it to the gas station?
What would your plan of attack be?Find how much gas was used the first ½,
and then how much gas can be used for the 2nd ½. From that gas you can get mpg from the ½ distance.
Now its your turn…I expect you to now write down/tape
in/etc the next problems.
You will start by attempting the problem individually, then after I give the signal, discuss it with group mates and come to an agreement.
Place agreed answer kinda small on the group whiteboard.
You try 1A Jerk is defined as an acceleration in a
given time. Which of the following is the correct unit for a Jerk? Show/write your reasoning.
A) m.sB) m/sC) m/s2
D) m/s3
You Try 2A)In rotational motion, objects have
a resistance to motion called I, the moment of inertia.
A solution for it is ½ mv2 = ½ I (v2/d2)
What dimensionality is I?
[M][L2]
You Try 3 NO MATHYou are going to Paris. You have $100 to
spend today. The rate of exchange is $1.24 per Euro. It costs 4 Euro to convert the money. You want to buy a 70 Euro Panda that also has 15% sales tax. Which of these is a correct process to see if you can afford it?A) Convert $100 to Euro’s, subtract 4 Euro, compare to 70 Euro that is multiplied by .15
B) Convert $100 to Euro’s, add 4 Euro, compare to 70 Euro that is multiplied by .15
C) Subtract 4 Euro from 70 Euro that is multiplied by 1.15, convert to $, compare to $100.
D) Multiply 70 Euro by 1.15, add to 4 Euro, convert to $, compare to $100.
Now about UNITSUnit Represents
Meters: m Length, how far
Seconds: t Time, how long
Kilogram: kg Mass, how much stuff
Meter per Second: m/s Velocity, how fast
Meter per Second per Second: (m/s)/s m/s2
Acceleration, how quickly you change velocity
And prefix in unitsWe use prefix for different amounts
Prefix and symbol Relationship
Centi: c ex: cm 100 centi in a standard, 100 cents in 1 dollar
Milli: m ex: ms 1000 milli in a standard 1000 years for a millenium
Kilo: k ex: km 1000 standard in a kilo $100k is $100,000
Example: 1.2 km is how many cm?
120,000cm
On the Board 1A)Going from m/s to km/hr, will the
result increase or decrease? Explain your answer
B) Going from cm/hr to m/min, will the result increase or decrease? Explain your answer
On the Board 2Your tank holds around 18.6 gallons
of gas, but shows it to be exactly ¼ full. The next gas station is 73 miles away. You drive so your car gets 14mpg for the first ½ of that distance. What mpg do you need for the 2nd half to just make it to the gas station?
17.86mpg
On the Board…From your PacketA car on a highway is on average 4.4
meters long. It is assumed that cars go a constant 75 km per hour. Each car is expected to be 2 seconds apart. How many cars can pass a point on a highway in hour?
Hint: Determine the space needed for 1 car first.
1628 cars
ApplicationYou will start with the homework
given out right now (Dimensional Analysis)
The purpose is to give you a sense of how to analyze a situation and determine where to start.
Try the 1st 3 on a separate paper. Either individually or in groups.
1st Three…VOTINGLets see if you came up right
answers.Vote on what you got for the 1st one
A) 90 CleansB) 270 CleansC) 0 Cleans
1st Three…VOTINGLets see if you came up right
answers.Vote on what you got for the 2nd one
A) 80 ZitsB) 240 ZitsC) 0 Zits
1st Three…VOTINGLets see if you came up right
answers.Vote on what you got for the 3rd one
A) 1.77 ZitsB) 2.66 ZitsC) 0 Zits
FinallyThe QR code is linked to the wiki I
set up where there will be answers, documents, and the videos I make and reference for this class.
