WELCOME TO PHYSICS!

1. 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.

2. What you need for class • 1 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

3. Syllabus and More • What is important…. • For next class….. • 1) Letter signed • 2) Questionnaire Done • 3) Day 1 Assignment Finished, Checked • 4) Day 2 video watched/checked

4. What will happen today? • We are going to begin our study of physics. • 1) Reviewing Dimensionality • 2) 3 Examples done by me • 3) 3 Examples done by you, confirmed by group • 4) 2nd Learning/Review session of units and our first major set of definitions • 5) 4 Group led problems on small boards • 6) Our first application activity • 7) Summary, link to website

5. My Goals For Today • At 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.

6. Lets Start…DIMENSIONAL ANALYSIS • What is it? • Converting between units through math • Strategies • 1) Identify what unit you are going to change and the result unit. • 2) Write it out the way I will show you • 3) If you have NO idea what is being asked, it is good to try to use dimensional analysis as a start point.

7. Who gives a flying fig? • It is really easy to screw up the conversions OR make a wrong assumption. • Mars Climate Orbiter

8. Example One • Last week, my trail ride was around 16 miles per hour. How many feet per second is that? • 23.4 feet per second

9. As your packet stated • 3 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

10. Example Two • A car driven by a distracted panda goes from speed vito vfover 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 – vi2) 2 • B) mp (vf2 – vi2) 2d • A) mp (vf – vi) 2 • A) mp (vf – vi) 2d • B…this is a released question

11. Example 3 VOTING • Your 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.

12. 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.

13. You try 1 • A 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.s • B) m/s • C) m/s2 • D) m/s3

14. You Try 2 • A)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]

15. You Try 3 NO MATH • You 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.

16. Now about UNITS

17. And prefix in units • We use prefix for different amounts Example: 1.2 km is how many cm? 120,000cm

18. On the Board 1 • A)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

19. On the Board 2 • Your 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

20. On the Board…From your Packet • A 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

21. Application • You 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.

22. 1st Three…VOTING • Lets see if you came up right answers. • Vote on what you got for the 1st one • A) 90 Cleans • B) 270 Cleans • C) 0 Cleans

23. 1st Three…VOTING • Lets see if you came up right answers. • Vote on what you got for the 2nd one • A) 80 Zits • B) 240 Zits • C) 0 Zits

24. 1st Three…VOTING • Lets see if you came up right answers. • Vote on what you got for the 3rd one • A) 1.77 Zits • B) 2.66 Zits • C) 0 Zits

25. Finally • The 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.