Presentation on theme: "Fri Sept 20th 1.Turn in notebooks moved to next Friday! –Make sure you have everything in your reference section –Make sure all assts are in chronological."— Presentation transcript:
Fri Sept 20th 1.Turn in notebooks moved to next Friday! –Make sure you have everything in your reference section –Make sure all assts are in chronological order –Makes sure nothing is in your pockets 2.UNIT TEST! –You will need your ruler & protractor –I will provide you with a calculator; PUT IT IN DEGREES ! –Cell phones in backpacks; both hands on desk at all times 3.Asst: Packet notes up to & including page 76 “Problem-solving strategy” (Write page numbers, as before!)
Monday Sept 23 6 th back in Math Lab; 1 st & 3 rd in lab on Tuesday 1.Collect stuff …. 2.Lecture Notes: kinematics equations, expectations, etc (see next slide!) 3.6 th period : Computers – FINISH “Speed” write-up; email home to print out & put in a plastic portfolio cover 4.1 st & 3 rd period : Lecture Notes on Accel of Gravity problems 5.Asst: Practice Problems WITHIN last night’s reading … #1-4 EVEN, 9-24 EVEN AND #23 Speed Write-ups due Friday in a plastic report/portfolio cover
Lecture notes Kinematics part 1: To the right are the 4 kinematics equations For each HW problem, you are to write out the knowns of the problems WITH UNITS –the 5 variable choices are d, v 0, v f, t, a You are to write the unknowns, & then = ? –example: a = ? You are to check that the units of all the knowns MATCH (or else use the FLM!!) You are to pick the correct equation based on your knowns and unknowns. Write the equation as you see it exactly at right. Write the equation again, but with the numbers plugged in. Solve for the first unknown. You must then solve for the 2 nd unknown too! Answers are on the handout #2 example: v 0 = 36 m/s v F = 15 m/s t = 3.0 sec a = ? d = ? v f = v o + at **must write out plug in numbers & solve d = ½ (v 0 + v f ) t **write out plug in numbers & solve Note: all variables are lower case, do not change the order of the eqs around, show 0’s plugged into equation where appropriate
Tues Sept 24 1 st & 3 rd in math lab; 6 th in classroom 1.Organize binders: Move “Current” divider back to after kinematics Do you have the “Experiment Write-up Rubric” in your Reference section? Are there any more handouts or assts from the last unit that I should have? 2.Questions on HW; turn in 3.1 st & 3 rd : finish Average Speed write-up 4.6 th : Lecture Notes – gravity problems 5.Asst: Problems wrksht B, skip 4, 5, 6, 12
Kinematics lecture notes part 2: –Objects under the influence of gravity Lecture Notes are posted separately on the webpage!
#11: High popup remains in air for 6.0 seconds. Distance to top: There are TWO okay ways to do this: Look at it on the way up: v naught unknown v final = 0 (at max ht) time = 3 sec a = neg 9.8 d = ? (will give you a positive number) OR: Look at it on the way down: v naught = 0 v final = unknown time = 3 sec a = neg 9.8 d = ? (should give you a negative number) height is the absolute value of d, so it SHOULD be positive 44 meters (answer slightly wrong) #12: Number 12 is a THREE-STEP problem….. 1) It is dropped from 1.20 m: v naught = 0 d = NEGATIVE 1.2 a = negative 9.8 v final = ?? (this is question a) NOTE ****** If you use vf^2 = vo^2 + 2 ad, then to solve this you have to square root as the final step. BUT, a square root ALWAYS has 2 answers, both positive & negative! In this case, the object is going DOWN, so the correct answer is the negative one! LOTS of points taken off on the test for that, when its done wrong! 2) It rebounds to a height of 1.00m: v final = 0 (at max ht) v naught = ? (this is answer b, and should be positive, because its UP) a = negative 9.8 d = positive 1.00 3) In the split-second while it is in contact with the ground, what is the accel? Well, the v final from part a is now the v initial of THIS part, right? AND, the v naught from part b is now the v final of this part, right? (Close your eyes and concentrate on what's happening and THINK about that!) So, now you know both v's, and know t = 0.010 sec, and can get accel. NOTE - make sure your math works out EXACTLY CORRECTLY to get my answer, or you've done something slightly wrong! IF you ever find yourself trying to take the square root of a negative number, YOU'VE DONE SOMETHING WRONG! It is almost always that you've missed something that is supposed to be negative. Remember: down is negative! So if it falls, the d is down, AND the v final is down, so both of those are negative. On the unit test, I usually end up taking off lots of points for significant figures and NEGATIVE signs, so pay careful attention to those so that you don't miss those points.
Wed Sept 25 (collab day) 1.Do these 2 problems in your lecture notes quietly 1.A student pushes upwards off a diving board that is 10.0 meters above the water at 2.00 m/s. What is their total time in the air, and their final velocity right before they hit the water? 2.A space ship is traveling 25 m/s, when it starts experiencing an acceleration of -4.0 m/s 2. What is its velocity and displacement after half a minute? 2.Questions on yesterday’s asst (wksht B)? 9b) d = - 30 m; 11) if you solve it for the way down (easier), you get - 44 m, but it actually “rose” + 44 m; initial & final vel = ± 29 m/s 13b) d = - 78 m; 16a) this question did NOT ask “total time in the air”, so the answer is only 2.8 seconds, but if it DID ask “total time in the air” you would have to multiply by 2 to get 5.6 seconds! 3.Work on today’s asst: 1.Brief NOTES from the front side of sheet 4 (“Accel due to Gravity”) 2.Wrksht B 4-6 (4) 1.2 s, -2.0 m/s; (5) -78 m/s, -310 m; (6) -15.3 m/s; 1.56 sec 3.on the third SHEET of paper in your packet, the front side: Concepts 8-10, 6-8; and on the same page, Problems 9, 17a, 18, 20, 22, 24 **If you have more time, work on Thur’s asst: wrksht C 13- 20** ALL, 2-12 even (**important!!!!) Test Friday October 4th 4 parts: horizontal problems, vertical problems, concept questions from sheet 3, last question is about the experiment
Thurs Sept 26 1.Binders: did you … put Experiment checklist in Reference; move Current divider BACK behind last unit; do you have ALL the daily agendas? – COLLECTED FRIDAY 2.Go over yesterday’s HW questions (concepts!) Brief NOTES Accel due to Gravity Wrksht B 4-6 (4) 1.2 s, -2.0 m/s; (5) -78 m/s, -310 m; (6) -15.3 m/s; 1.56 sec on the third SHEET of paper in your packet, the front side: Concepts 8-10, 6-8; and Problems 9, 17a, 18, 20, 22, 24 3.QUIZ 4.Asst: worksheet C 13-20** ALL, 2-12 even (**important!!!!) 5.Write-ups due too! Test Friday October 4th 4 parts: horizontal problems, vertical problems, concept questions from sheet 3, last question is about the experiment
Fri Sept 27 1.Binders collected today at end of period!!! 2.Look at last test briefly. 3.Self-correct “Quiz” in RED. Basically its 1 point for each known (as long as you have a negative sign when there should be one) and each unknown (must have a question mark!) Its 1 point for each correct equation (it does not necessarily have to be the same one I used!) used to solve for an unknown Its 1 point for showing your math-work/numbers plugged into each of the equations Its 1 point for the correct answer WITH units & significant units (it must be negative if mine is; it may be SLIGHTLY different than mine if clearly supported by your equation & your math!) Give yourself a total score and a percent (out of how many YOU completed) Quizzes are to be turned in after you are done. 4.With the rest of your class time, start the “Prelim exercise” in preparation for Monday’s experiment – EACH person collects their OWN data quietly from the picture and to the 0.1 mm. (We will actually roll things down incline planes in class Monday and collect REAL data too!) 5.HW: (a)finish prelim exercise (all data & 2 graph sketches) (b)Sheet 3, right column # 9, 12, 13 + back of sheet 3 (ditto “A”) #2-4 (That’s 6 kinematics problems total) Ditto A #4b) How far move AFTER 3.6 sec Test Friday October 4th 4 parts: horizontal problems, vertical problems, concept questions from sheet 3, last question is about the experiment
Mon Sept 30 1.In class: Average Accel experiment 2.HW: ditto D (find both unknowns) skip: 33, 34, 38, 41; do 30-32, 35, 37, 39-40; 54-57 & 60 EMAIL ME ANY QUESTIONS ABOUT THESE; there won’t be time in class to answer questions! (Odds are that the one you can’t do will appear on the unit test!) Test Friday October 4th 4 parts: horizontal problems, vertical problems, concept questions from sheet 3, last question is about the experiment
Tues 10/1 ***SIT WITH YOUR LAB PATNERS FROM FRIDAY!*** 1.Collect HW? (ditto C and D??) 2.Computer lab – Average Accel data 3.HW a: Experiment Write-up Title-Procedure (see email for hints) Handwritten, neatly, skipping lines, bring in tomorrow 4.HW b: PRINT OUT STUDY GUIDE! Test Friday October 4th 4 parts: horizontal problems, vertical problems, concept questions from sheet 3, last question is about the experiment from today
Wed 10/2 SIT WITH LAB PARTNERS AGAIN! 1.Collect HW? (ditto C and D??) 2.Computer lab – Average Accel data CHECK DATA against sheet handed out yesterday (checklist) Email data home (will need to be printed on color printer!) Work on hand-written write-up (Results & Conclusions) when done w/ data 3.Asst: Redo ditto C probs 13-20 ALL, and 1-12 odd (new, better sheet provided**) a.List knowns & unknowns b.Write the equation before you plug numbers in! c.Plug numbers in and solve d.TAKE THIS LIKE A PRACTICE TEST! (We will grade it like one tomorrow! 4.MAKE SURE STUDY GUIDE IS PRINTED OFF! Test Friday October 4th 4 parts: horizontal problems, vertical problems, concept questions from sheet 3, last question is about the experiment from yesterday & today
Thurs 10/3 1.Hand back papers 2.Grade ditto C as “Practice test” ** Teacher will read off knowns & unknowns (+ 1 for each that is correct) 1 point for each correct equation used, IF KNOWNS ARE CORRECT! 1 point for showing math-work/numbers plugged into ea. equation Teacher will read off answer (1 point ea. IF has units & significant figs) ***Discuss how to do #20 if “descending” instead 3.Go over Preliminary Exercise & Study Guide (see next slides) 4.HW: (a) Finish Average Acceleration Write-up if must (b) Retake the quiz from last week, covering up the answers. Check it after you’re done! Watch the tricky times, and all those negative signs! (c) Study the concepts (see Study Guide)
Study Guide for Unit 2 (Kinematics) Test: A) Approximately 5 questions dealing with objects moving horizontally. Study packet problems about people, cars, trains, planes, etc. Approximately 5 more questions dealing with objects moving vertically, where the acceleration is always –9.8 m/s2. Study ditto B (and your quiz!) in particular. (Ditto C has a nice combination of both horizontal & vertical problems, similar to what you might see on the test. However, be careful of the answers given – both numerically and because of sig figs.) B) ALSO: Some “Conceptual questions: Know about the velocity(s) of an object as it is shot straight up into the air AND as it falls back down. Use the words positive, negative, speeding up, zero, and slowing down. Know about the acceleration of an object as it is shot straight up into the air AND as it falls back down. Know about how the acceleration of gravity effects the total time in the air & the height they would be able to reach. (ie: if it were less than 9.8 as it is on the moon, would time in the air be more or less, would height it attains be more or less?) What falls faster, a heavier object or a lighter object? (Hint: think about the acceleration of gravity in both cases. Is this a trick question?) C) Know about your Average Acceleration experiment: (Pictures and examples are always helpful to show complete understanding.) In 5 words or less, what did you do? (hint: cart, incline) What data was collected by the computer/LoggerPro/Photogate/picket-fence system (hint: look at the axes of your graphs!) Of the two answers for b above, what was graphed on which axis (use the words dependent & independent) How did you determine the acceleration from this graph (what did you do to it EXACTLY and what did you look at SPECIFICALLY). What is the definition of acceleration? How does this equation (in e above) compare with what you looked at on the graph to determine the acceleration? (Hint: Slope = ___ / ___ )
Friday Oct 4th 1.Test: need pencil & calculator Note: Essay make-up test if absent for 2 tests in a semester. I’ll be coming around asking you to show me your hands to make sure you don’t have the equations written on them! 2.HW: Roller coaster Note: need handout + 3 sheets graph paper HW b: NOTES in book pages 38, 40, 42, 62 (copy all graph figures/pictures AND the captions that go with them! This is the most important part of those notes!)