Internet web site www unit 5 orgchemistry Welcome
Internet web site: www. unit 5. org/chemistry/
Welcome to Mr. Erwin’s Physics Class The science at the heart of all other science
Getting to know me…. . • Tim Erwin (Mr. Erwin) • Wife: Mrs. Erwin (new music/drama teacher) • Dogs: Rabbit and Lyric • Hobbies: Kayaking, hiking, sport and Scuba diving, and watching sports • B. S. Aerospace Engineering from UC San Diego • Previously managed a building supply and lumber yard in Gualala, CA • Teaching 8 th grade science, Physical Science, Engineering, and Physics
What will we be doing/learning this year: – Studying natural phenomena, forces, energy, heat, light, sound, matter and change – We will use a small number of basic concepts, equations, and assumptions to describe the physical world – We will use physics principles to make predictions about motion, forces, energy, light and electricity – In Physics we will use math to problem solve and predict outcomes Sometimes tough… but very cool stuff!
Proficiency Grading • • Course Component % of Grade Homework /Class Work 15% Inquiries/Labs 15% Proficiency Assessments 70% What is the proficiency grading scale? – A = 90 -100 – B = 80 -89 – C = 70 -79 *Less than 70% fails to meet proficiency and you will receive a zero until you make up proficiency assessment (exams/tests)
Proficiency Grading Assessment: This course will be graded based on the student demonstrating proficiency of content knowledge and concepts through proficiency assessments (exams/tests). In class assignments & homework will only be worth 15% of the grade. Labs will also be worth 15%. Completing homework and in class assignments are for practice and developing understanding & proficiency, they do not demonstrate proficiency. Your homework and in class assignment grades are therefore only worth 15% of your grade for the semester. Your homework/assignment grades will be based on completion. EXPECT REGULAR HOMEWORK.
Proficiency Grading • Tests/Exams (70%): Tests and Exams will be given at the end of each unit. They are used to demonstrate proficiency of the concepts and skills covered during the unit. • Calculators and approved handouts may be used on some exams. (No cell phones for calculators) • Retakes: All proficiency tests and exams can be re-taken as many times as required until proficiency is met, up to four weeks after the initial assessment was given. After two attempts you may use open notes during the exam but your highest possible score will be 70%. • You must correct all wrong answers on the first failed assessment and explain your understanding of the correct answer before attempting a retake. • The corrections and retakes must be done on your time after school during office hours: 3: 15 to 4: 00 pm Weds & Thurs.
My Teacher WEB Site • Located on the CMHS WEB site. Select the link for Staff on the left. Scroll down and select “Erwin, Tim” and then the “Courses Website” link on my page. • http: //clatskaniehigh. or. ch. schoolinsites. com/ • • • Use it to access lecture notes Use it to study Use it to download assignments (if posted) Use it to review class standards and policy Use it to learn more about your teacher (me).
How to succeed in Mr. Erwin’s class • • Come ready to learn and work Follow class rules and procedures Do your work on time Do your best I will listen to you and treat you fairly when you do the above
Daily Journals/Lab Note Book • Every day you make an entry in your journal. If you have them, open up your note books and start your journals now. Otherwise bring in tomorrow. • Copy down the date, agenda, lesson objectives and warm-up questions & answers. • Each day you should start a new section or page with the date as the heading and the daily agenda copied from the blackboard • You should record notes on information presented verbally, on the board, by overhead, movie, filmstrip, lecture, etc. in your journal.
How you will Learn Before Class: Review previous notes Read over old material Read new material During Class: TAKE NOTES! ASK QUESTIONS! ANSWER QUESTIONS! After Lecture: Use class time to start worksheets/homework. Ask for help Work together
How to do well on evaluations: Quizzes: Bring your notes- some may be open note Labs: Read the introduction Take careful measurements Show your work Complete all parts of the lab Ask questions Tests: Review notes Study together Complete your homework before the due date Review quizzes and Labs Get help before school at lunch or after school
Mr. Erwin’s Classroom Rules Rule #1 Be on time and in your seat before the tardy bell rings. Rule #2 Raise your hand for permission to speak or to leave your seat. Rule #3 Be responsible. Rule #4 Make smart choices. Rule #5 Respect everyone! Rule #6 Keep Mr. Erwin happy.
Safety
DANGER Laboratory Safety Rules
SAFETY in the Science Classroom Obey the safety contract – Use common sense – No unauthorized experiments – Wear safety glasses – Safety is an attitude! – Don’t take anything out of lab – Read and follow all instructions
Basic Safety Rules #1 Rule: Use common sense. Others: No horseplay. No unauthorized experiments. Handle chemicals/glassware with respect.
Safety Features of the Lab safety shower fire blanket fire extinguisher eye wash fume hoods circuit breaker switch
Safety Equipment Safety Goggles Fire Extinguisher Type A Type B Type C Safety Shower
Know the Location of Safety Equipment • Let Mr. Erwin know of any accident!!! • Fire extinguisher • Fire blanket • Eye wash & Shower • Fume Hoods
Know where not to go. Storage Room • No students are allowed in the storage room without a teacher’s permission. • Except in an emergency where someone needs help or when helping a teacher.
Accident/Emergency Procedures • Safety begins with the proper attitude. Don’t panic, keep calm and quiet and wait for instructions. • Always err on the side of safety. It’s not wrong if it’s cautious. • If evacuation is required, your job and duty is to get to a safe location and to allow staff to do the jobs they are trained for. • If an accident occurs, let Mr. Erwin know immediately, he will get you help. You will not be in trouble!
Emergency Exits • Know evacuation routes. • Take nothing other than clothing at immediate hand (on you or next to you) • Go straight out the exit. Never stop at a locker go to the bathroom or wait for friends. • Assemble with your class at the designated assembly area
Why do we care? ? ? http: //www. nclark. net/Lab_Safety. wmv. Flammable Chemical Burns Health Reactive Special Disfigurement Chemical burns on feet. Death!! Skin burned by chemicals
Safety Pre Quiz • Lets See how much you already know • When done with the quiz, turn it in up front and pick up the handout, “Science Safety Rules” • When done reading, raise your hand, I will give you a quiz to grade.
Material Safety Data Sheet (MSDS) -- gives information about a chemical -- lists “Dos” and “Don’ts; ” emergency procedures
Chemical Exposure acute exposure a one-time exposure causes damage e. g. , reaction to drugs or medication chronic exposure damage occurs after repeated exposure e. g. , smoking, asbestos
LD 50 the lethal dosage for 50% of the animals on which the chemical is tested There are various ways an LD 50 can be expressed. For example, acetone has the following LD 50 s: ORL-RAT LD 50: 5, 800 mg/kg IHL-RAT LD 50: 50, 100 mg/m 3 -h SKN-RBT LD 50: 20 g/kg
Example Chemical A: LD 50 = 3. 2 mg/kg Chemical B: LD 50 = 48 mg/kg Which is more toxic? Chemical A is more toxic because less of it proves fatal to half of a given population.
The Scientific Method
The Scientific Method • • • Observe an unknown & ask A Question Form Hypothesis (An educated prediction) Experiment & Test Hypothesis Collect Data Analyze Results Draw Conclusions & Communicate Results *Remember the acronyms: OHEDAC or OHEDACC
** Key: Be a good observer. observation uses the five senses inference involves a judgment or assumption
Types of Data Observations are also called data. qualitative data -- descriptions e. g. , clear liquid quantitative data -- measurements e. g. , 55 L or 83 o. C
Parts of the Scientific Method Observe & Identify an unknown (Ask a question). Make a hypothesis: a testable prediction Repeatedly experiment to test hypothesis. procedure: order of events in experiment (i. e. , a recipe) variable: any factor that could influence the result
A Scientific Experiments must be controlled: they must have at least two set-ups that differ by only one variable conclusion: must be based on the data
Scientific Law vs. Scientific Theory law: states what happens -- does not change -- never violated -- e. g. , law of gravity, laws of conservation theory: tries to explain why or how something happens -- based on current evidence -- e. g. , Theory of Gravity, Atomic Theory
Recap What is Physics? – The study of natural phenomena of basic things such as motion, forces, energy, matter, heat, sound, light, and the composition of atoms 2. What branches of science use physics? – All branches! 3. What are the steps in the Scientific Method? *Remember OHEDAC – Observe an unknown & ask A Question – Form Hypothesis (An educated prediction) – Experiment & Test Hypothesis – Collect Data – Analyze Results – Draw Conclusions & Communicate Results 4. What is the difference between a law vs. theory? – Law: States what happens – Theory: Tries to explain why or how something happens
Manipulating Numerical Data
Graphs
Bar Graph # of students shows how many of something are in each category
Pie Graph shows how a whole is broken into parts Percentage of Weekly Income
Line Graph shows continuous change Stock Price over Time In chemistry…you will always use a line graph.
Elements of a “good” line graph 1. title 2. axes labeled, with units 3. neat 4. use the available space
Essential Math of Physics
Scientific Notation -- used to express very large or very small numbers, and/or to indicate precision (i. e. , to maintain the correct number of significant figures) Form: (# from 1 to 9. 999) x 10 exponent 800 = 8 x 102 2531 = 2. 531 x 10 = 2. 531 x 103 0. 0014 = 1. 4 10 10 10 = 1. 4 x 10– 3
Put in standard form. 1. 87 x 10– 5 = 0. 0000187 3. 7 x 108 = 370, 000 7. 88 x 101 = 78. 8 2. 164 x 10– 2 = 0. 02164 Change to scientific notation. 12, 340 = 1. 234 x 104 0. 369 = 3. 69 x 10– 1 0. 008 = 8 x 10– 3 1, 000, 000 = 1 x 109 6. 02 x 1023 = 602, 000, 000, 000
Using the Exponent Key EE EXP
The EE or EXP or E key means “times 10 to the…” How to to type out 6. 02 xx 10 102323: : 6 0 . 2 EE 2 3 not… WRONG! 6 0 . 2 yx 2 3 WRONG! or… 6 . 0 2 x 1 and not… 6 . 0 EE 2 3 TOO MUCH WORK. 0 2 x 1 0 yx 2 3
Also, know when to hit your (–) sign. (before the number, after the number, or either one)
1. 2 x 105 2. 8 x 1019 Type this calculation in like this: 1 . 2 EE 5 2 . 8 EE 1 9 = Calculator gives… 4. 2857143 – 15 or… 4. 2857143 E– 15 This is NOT written… 4. 3– 15 But instead is written… 4. 3 x 10– 15 or 4. 3 E – 15
7. 5 x 10– 6 (– 8. 7 x 10– 14) = – 6. 5 x 10– 19 4. 35 x 106 (1. 23 x 10– 3) = 5. 35 x 103 or 5350 5. 76 x 10– 16 9. 86 x 10– 4 = 5. 84 x 10– 13 8. 8 x 1011 x 3. 3 x 1011 = 2. 9 x 1023
Essential Math of Physics
Units must be carried into the answer, unless they cancel. 5. 2 kg (2. 9 m) = 0. 64 kg-m (18 s)(1. 3 s) s 2 4. 8 kg (23 s) (18 s)(37 s) = 0. 57 kg s
Solve for x. x+y=z x and y are connected by addition. Separate them using x + y = z subtraction. In general, use –y –y opposing functions to separate things. The +y and –y cancel on the left, leaving us with… x=z–y
Numerical Example Solve for x. x – 24 = 13 x and 24 are connected by subtraction. Separate them using the opposite function: addition. x – 24 = 13 +24 The – 24 and +24 cancel on the left, leaving us with… x = 37
Solve for x. x and k are connected by multiplication. Separate them using the opposite function: division. The two k’s cancel on the right, leaving us with… F=kx () () __ 1 F=kx k k (or) F=kx k k __ F x= k
Numerical Example Solve for x. x and 7 are connected by multiplication. Separate them using the opposite function: division. The two 7’s cancel on the right, leaving us with… 8=7 x () () __ 1 8=7 x 7 7 (or) 8=7 x 7 7 __ 8 x= 7
Solve for x. One way to solve this is to cross-multiply. Then, divide both sides by TR. The answer is… ___ BA = ___ TR x H BAH = x. TR ( ) ___ 1 BAH = x. TR ___ 1 TR TR BAH x = ___ TR
Solve for T 2, where… P 1 V 1 ____ = P 1 = 1. 08 atm T 1 P 2 = 0. 86 atm ____ 1 PVT = V 1 = 3. 22 L P 1 V 1 1 1 2 V 2 = 1. 43 L T 1 = 373 K ( ) P 2 V 2 ____ T 2 ( ) 1 P 2 V 2 T 1 ____ P 1 V 1 P 2 V 2 T 1 ______ T 2 = P 1 V 1 (0. 86 atm)(1. 43 L)(373 K) ___________ T 2 = = 132 K (1. 08 atm)(3. 22 L)
SI Prefixes kilodecicentimilli- (k) (d) (c) (m) 1000 1/ 1000 Also, 1 m. L = 1 cm 3 and 1 L = 1 dm 3
Conversion Factors and Unit Cancellation
How many cm are in 1. 32 meters? equality: 1 m = 100 cm (or 0. 01 m = 1 cm) conversion factors: ______ 1 m 100 cm or ( 100 cm ______ 1 m ) 100 cm = 132 cm 1. 32 m ______ 1 m We use the idea of unit cancellation to decide upon which one of the two conversion factors we choose.
How many m is 8. 72 cm? equality: 1 m = 100 cm conversion factors: ______ 1 m 100 cm or ( 100 cm ______ 1 m ) 1 m 8. 72 cm ______ = 0. 0872 m 100 cm Again, the units must cancel.
How many kilometers is 15, 000 decimeters? ( )( 1 m 15, 000 dm ____ 10 dm ) 1 km ______ = 1. 5 km 1, 000 m
How many seconds is 4. 38 days? ( )( 24 h 4. 38 d ____ 1 d )( ) 60 min _____ 1 h 60 s ____ = 378, 432 s 1 min If we are accounting for significant figures, we would change this to… 3. 78 x 105 s
Simple Math with Conversion Factors
Find area of rectangle. 4. 6 cm A=L. W = (4. 6 cm)(9. 1 cm) = 42 Convert to m 2. Convert to 9. 1 cm 2. cm cm mm 2. cm. cm 1 m 42 cm 2 ______ 100 cm 42 cm 2 ( ) = 0. 0042 m 2 ( ) = 4200 mm 2 10 mm ______ 1 cm 2 2
For the rectangular solid: Length = 14. 2 cm Width = 8. 6 cm Height = 21. 5 cm Find volume. V=L. W. H = (14. 2 cm)(8. 6 cm)(21. 5 cm) = 2600 cm 3
Convert to mm 3. 2600 cm 3 ( ) 10 mm ______ 1 cm 3 = 2, 600, 000 mm 3 = 2. 6 x 106 mm 3 mm and cm differ by a factor of………. 10 mm 2 “ cm 2 “ “ “ ………. 100 mm 3 “ cm 3 “ “ “ ………. 1000
How many feet is 39. 37 inches? equality: 1 ft = 12 in applicable conversion factors: ______ 1 ft 12 in X ft = 39. 37 in or 12 in ______ 1 ft ( ) ____ 1 ft = 3. 28 ft 12 in Again, the units must cancel.
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