RE 7.a. RE 7.b Energy Dissipation & Resonance RE 7.c EP7, HW7: Ch 7 Pr s 31, 32, 45, 62 & CP

Size: px

Start display at page:

Download "RE 7.a. RE 7.b Energy Dissipation & Resonance RE 7.c EP7, HW7: Ch 7 Pr s 31, 32, 45, 62 & CP"

Opal Cole
5 years ago
Views:

1 Wed. Lab Fi. Mon. Tue Macocopic Enegy Quiz 6 4pm, hee Math & Phy Reeach L6 Wok and Enegy Enegy Tanfe RE 7.a RE 7.b Enegy Diipation & Reonance RE 7.c EP7, HW7: Ch 7 P 3, 3, 45, 6 & CP

2 Molecule Ball-Sping Model Solid F=-k(- ) F good enough Moe emi-empiical appoximate Moe E M e EM E M =

3 Molecule Ball-Sping Model Moe emi-empiical appoximate Moe E M e EM Expeimentally detemining the contant E M = : Beak molecule E M = : Fo olid, fom denity and atomic ma Fo molecule: otational pectum (moe late) : Fom vibational pectum (moe now)

4 Molecule F Ball-Sping Model Finding : elating to ma-ping F=-k(- ) Taylo Seie Appoximation d d d F d at uilibium = 0 d d d d d F d k k d d M E M E M = =- k(-) Moe emi-empiical appoximate Moe E M ecall f k m e EM

5 Molecule Ball-Sping Model Potential Enegy in Solid Solid bond. olid k Nbond N bond bond olid bond total Aea Recall: ktotal k Length k N k bond total

6 epulive uilibium attactive Sytem= weight + ping Sping foce and potential Active envionment = none E 0 W ytem ext, E d, F. k k E E W, S Eet. W Eet. S KW K S W, S E Negligible ma W, S KW W, S 0 k k 0 m wvw. f mwvw. i f i A hoizontal ping with tiffne 3 N/m ha a elaxed length of 5 cm (0.5 m). A ma of 50 gam (0.050 kg) i attached and you tetch the ping to a total length of 9 cm (0.9 m) The ma i then eleaed fom et and move with negligible fiction. What i the kinetic enegy of the ma at the moment when the ping etun though the poition it uilibium length, 5 cm? ).4e-3 J 3) 6e- J 5).5 J ) 4.8e-3 J 4).6e- J 0

7 Hoizontal Ball on ping K K+ E. ball on ping enegy foce momentum.py

8 Conide a block falling onto a vetical ping. State: A: Block 0.8 m above floo B: Block jut touching top of ping C: Block come to et To find the peed of the block jut befoe it hit the ping, what hould we pick fo initial and final tate? Initial Final ) A B ) B C 3) A C 4) C A

9 Conide a block falling onto a vetical ping. State: A: Block 0.8 m above floo B: Block jut touching top of ping C: Block come to et To find the maximum compeion of the ping, what hould we pick fo initial and final tate? Initial Final ) A B ) B C 3) A C 4) C A

10 Ball-Sping Model Kinetic Enegy in Solid

11 Molecule Ball-Sping Model Themal Expanion Fo highe enegie, aveage bond length i geate L o L ((K+) Hi ((K+) medium ((K+) Lo L popotional to E Themomente: T popotional to L L popotional to E T popotional to E

000 gam of wate inceaed 7000 J. What wa the tempeatue inceae in Kelvin of the wate?

12 Heat Capacity T popotional to E int E int CT C = Heat capacity C hould be mateial pecific and cale with amount of mateial int C c v m E cvmt c v = (ma) pecific Heat capacity The themal enegy of the 000 gam of wate inceaed 7000 J. What wa the tempeatue inceae in Kelvin of the wate? The heat capacity of wate i c v = 4. J/K on a pe-gam bai. ) K ) 0.6 K 3).7 K 4) 667 K 5) Inufficient infomation

13 Say you do the hitoic falling-weight / paddle-wheel in bucket expeiment. The ma dop, the wheel pin, and the 0 kg of wate wam up. We find that the diffeence between the change in gavitational potential and change in kinetic enegie i J. A themomete tuck in the wate tell you that it tempeatue ha ien T=0.96 Kelvin. What the ma-pecific heat capacity of wate?

14 Wed. Lab Fi. Mon. Tue Macocopic Enegy Quiz 6 4pm, hee Math & Phy Reeach L6 Wok and Enegy Enegy Tanfe RE 7.a RE 7.b Enegy Diipation & Reonance RE 7.c EP7, HW7: Ch 7 P 3, 3, 45, 6 & CP

15 epulive attactive epulive d Foce a negative gadient (3-D lope) of Potential Enegy F d mall change in potential F dx F dy F,. x. y. z o dz, F d,, F. x, F. y, F. z,, x dy d dz, d dx, F. x xˆ xˆ Which of the following expeion atifie the uiement that F x d / dx k whee x i meaued fom the uilibium poition (C i a contant)? x ) ) 3) 4) 5) k k k x k C x k x C C C C

16 Molecule Ball-Sping Model Solid F=-k(- ) F, F d =- k(-) E M = Moe emi-empiical appoximate Moe E M e EM

17 Two lead bick moving in the +x and x diection, each with kinetic enegy K, mah into each othe and come to a top. What happened to the enegy? ) The obevable kinetic enegy changed to themal enegy, a fom of et enegy. ) The total enegy of the ytem deceaed by an amount K. 3) Since the block wee moving in oppoite diection, the initial kinetic enegy of the ytem wa zeo, o thee wa no change in enegy.

Force & Motion: Newton s Laws

Force & Motion: Newton s Laws oce & otion: Newton Law ( t Law) If no net foce act on a body then the body velocity cannot change. Zeo net foce implie zeo acceleation. The ma of an object detemine how difficult it i to change the object