#### Transcript DO NOW

Chapter 11, Lesson 2: May 1 & 2 HW Due Read & Study 11.1 - 11.3. Do #1-6, 21 – 24, 26, 33 (p. 165–66) (13 pts – 1 pt each and 1 pt for 1 graded on correctness) Tonight’s HW Read & Study 11.4 - 11.7 – Do #7 – 15, 17 – 20 (p. 165-66) (14 pts – 1 pt each and 1 pt for 1 graded on correctness) Don’t forget – test on Ch. 9 & 10 May 7(A) & 8(B) Finish your study guide by the END of class May 5(A) & 6(B) for +5! Do Now Take a clicker… Take a DO NOW from my desk! DO NOW: What is the weight of the unknown box? 0% 0% 100% 0% 0% 0% 0% 0% 0% A. B. C. D. E. F. G. H. I. 4.5 N 60 N 160 N 240 N 540 N 1800 N 4800 N 10,800 N None of the above What is the weight of the unknown box? First, let’s check…which object has a larger lever arm? So…which force has to be larger? So we know our ‘mystery weight’ is MORE than 120 N F x 30 cm = 4800 N cm Divide both sides by 30 cm …. Force = 160 N DO NOW: A meter stick is balanced as shown. If a 200 gram mass is placed at the 20 cm mark (30 cm from the turning point), at what mark should a 500 gram mass be placed so that the system balances? 10% 81% 0% 5% 5% 0% 0% A. B. C. D. E. F. G. 8 cm 12 cm 50 cm 62 cm 4000 cm 6000 cm None of the above DO NOW: A meter stick is balanced as shown. If a 200 gram mass is placed at the 20 cm mark (30 cm from the turning point), at what mark should a 500 gram mass be placed so that the system balances? First, let’s check…which object is the bigger force / weight?? So…which lever arm has to be larger? So we know our 500g’s LA MUST be smaller than 30 cm DO NOW: A meter stick is balanced as shown. If a 200 gram mass is placed at the 20 cm mark (30 cm from the turning point), at what mark should a 500 gram mass be placed so that the system balances? Divide both sides by 500 g …. LA = 12 cm BUT WE ARE NOT DONE! DO NOW: A meter stick is balanced as shown. If a 200 gram mass is placed at the 20 cm mark (30 cm from the turning point), at what mark should a 500 gram mass be placed so that the system balances? The question asks at what mark should it be placed? If it’s suspended from 50 cm… Then 50 cm + 12 cm = The 62 cm mark! LAB PRACTICUM • Return your clickers • Arrange yourselves in groups of 1 – 5 at desks or lab benches • Only items allowed out are a PEN and CALCULATOR… NOTHING ELSE! – Must use a calculator that is NOT your phone or iPod – MAY NOT USE NOTES OR BOOK – May have a piece of loose leaf, or teacher will give you a piece of scrap paper. • Follow all directions on the graded form. When you are ready to test your set up, call the teacher over. • When done, review your HW from last night with your group. • 10 minutes total to complete – failure to do so = 0/25! Take out the HW from last night • Cross off #24 • The next slide will contain the answers for your HW • Consider it to be like a word back – the answers are not in order • Your answer wording might vary slightly…and that’s OK! • Check and make corrections with your peers! • ANSWERS MEAN NOTHING if you don’t know HOW to get them! • Ask a teacher for help if needed!!! • 3 minutes • • • • • • #1-6 Perpendicular to LA CG They are equal Force changes velocity; torque changes rotation CG extends beyond area of support, producing a torque (due to gravity)…you fall! Distance from the axis/fulcrum to the force #21-23, 26, 33 • • • • • • • • • 2 kg Check your HW! 3m Answers NOT in order! 10 Nm 900 Nm each, 0 total 25 Nm 1.5 m 2m Longer feet = more area of support Longer handle for prying open; thicker handle for stubborn screws. Both provide bigger lever arms • • • • • POST LAB Timed assessment – you have 10 minutes Go to test seats - Open notes; NOT open text Can use a calculator Phones out and SILENT EXTRA CREDIT – YOU MUST SHOW WORK for each Mystery Box NEATLY and LEGIBLY in order to earn points – Attach loose leaf if you need more space • NO TALKING UNTIL TEACHER SAYS ITS OK – if you talk before you are given permission, you WILL LOSE POINTS. • When you are done, turn in post lab and take a copy of Ch 11 POGIL #2. SILENTLY return to test seat and work on notes. POGIL • Work efficiently – check in at stop signs • Whatever you do not get done today will be completed next class (the only HW you have tonight is from your book). • We are stopping with 3 minutes left for an exit • You have a TEST 2 classes from today…. Ensure that you are working to the best of your ability and getting the help you need!!! Exit Slip Take one, complete, & turn in NEXT CLASS • We will wrap up anything from today’s POGIL – (it is not HW if you don’t finish, but you do have questions from your book) • We will review the HW • You will have the remainder of class to work on your study guide • The study guide is due at the end of next class for +5 • Your HW next class will be to prep for the Ch 10 & 11 test