RE 6.d Electric and Rest Energy RE 6.e EP6, HW6: Ch 6 Pr s 58, 59, 91, 99(a-c), 105(a-c)

Transcription

1 ed. Lab., Mon. Tues. ed. Lab. Mon. Tues (.1) Intoducng Enegy & ok Quz 5 L5: Buoyancy, Ccles & Pendulums (.) Rest Mass,ok by Changng oces tudy Day tudy Day (.18,.19) Intoducng Potental Enegy The Thngs Physcsts & Engnees Do (.) Gavtatonal P.E. & Vsualzng RE 6.a laptop RE 6.b tudy Day tudy Day RE 6.c (last day to dop) RE 6.d Electc and Rest Enegy RE 6.e EP6, H6: Ch 6 P s 58, 59, 91, 99(a-c), 15(a-c) moton s nethe ceated no destoyed, but tanseed va nteactons. Momentum p mv v 1 c Enegy dt dt d E all all all dt d Impulse ok

2 Undestandng ok: cala o Dot Poduct as sum o poducts o components y z ŷ y z y y ˆ

3 ŷ' ˆ y' ' Undestandng ok: cala o Dot Poduct as pojecton o one vecto onto anothe poduct o magntudes and cosne ŷ ˆ z y z y cos z y z y

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5 Undestandng ok: conceptual non-physcst de Teache tudents ok E = E = Teaches Physcs Lean Physcs T

6 Undestandng ok: conceptual non-physcst de Teache tudents ok E = Zzzz Teaches Physcs Lean Physcs T Teaches Physcs Lean Nothng

7 Undestandng ok: conceptual non-physcst de Teache tudents ok Zzzz E = Teaches Physcs Lean Physcs T Teaches Physcs Teaches Nothng Lean Nothng Lean Physcs

8 Undestandng ok: conceptual non-physcst de E = B=NC 3 Teache tudents ok T?? Teaches Physcs Lean Physcs Teaches Physcs Teaches Nothng Lean Nothng Lean Physcs Teaches Physcs Unlean Physcs

9 Undestandng ok: conceptual non-physcst de E = C est un Gand Chen! Teache tudents ok Teaches Physcs Lean Physcs T Teaches Physcs Lean Nothng Teaches Nothng Lean Physcs Teaches Physcs Unlean Physcs Teaches Physcs Lean ench

10 Undestandng ok: conceptual non-physcst de E = C est un Gand Chen! Teache tudents ok Teaches Physcs Lean Physcs T Teaches Physcs Lean Nothng Teaches Nothng Lean Physcs Teaches Physcs Unlean Physcs Teaches Physcs Lean ench ok s the poduct o eot and achevement Both n the same decton, t s good (+) wok Both opposte dectons, t s bad (-) wok Both unelated dectons, t s no () wok One non-estent, t s no () wok

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12 ŷ ˆ ysphus Pushes ock uphll z s y z y... Rock goes up hll. + wok Rock stays put. wok Rock olls down hll. - wok Rock sldes sdeways. z wok Undestandng ok: conceptual physcst de

13 ŷ ˆ ysphus Pushes ock uphll z s y z y wok. wok. - wok. z wok ok s the poduct o oce and Dsplacement Both n the same decton, t s good (+) wok Both opposte dectons, t s bad (-) wok Both unelated dectons, t s no () wok One non-estent, t s no () wok Undestandng ok: conceptual physcst de

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15 On a space staton, you pushed a bo that was at est at locaton <,, 1 > m to locaton <,,14 > m, applyng a oce <,, 5 > N. How much wok dd you do on the bo? 1) = J ) = 5 J 3) = 7 J 4) = 14 J 5) Not enough nomaton Assumng no othe oces appled to the bo hat happened? 1) The bo slowed down. ) The bo sped up. 3) The bo moved at constant speed. Net you patne pushed back on the movng bo wth a oce <,, -3 > N. Ate the bo had moved om <,, 14 > m to <,, 16 > m. hat happened? 1) The bo slowed down. ) The bo sped up. 3) The bo moved at constant speed.

16 You move an object om < 3, 7, 4 > m to <, 1, 1 > m, applyng a oce < 1, -, 3 > N. How much wok do you do? 1) 1 J ) 17 J 3) < -1, -6, 4 > J 4) < 3, -14, 1 > J 5)

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18 Enegy E ok Enegy Relaton You won t have to do anythng lke ths o a ew yeas E v om o dt dt sub.-ng back n E 1 d d p / m p d 1 1 all d v 1 c ok d v dt mv p / m v whee p so v c d v c d p E 1 1 p 1 / p p

19 Q6..d: Consde an electon (mass 9e-31 kg) movng wth speed v =.9c. hat s ts total (patcle) enegy? 1) 7.3e-31 J ) 8.1e-14 J 3) 1.5e-13 J 4) 1.86e-13 J 5).7e8 m/s

20 Enegy E ok Enegy Relaton dt dt I v<<c d d p all mv d dt d v ok E v m dv v 1 mv 1 1 mv mv (appomate) Knetc Enegy

21 Q6..a: A ball whose mass s kg tavels at a velocty o <, 3, 4> m/s. hat s the knetc enegy o the ball? 1) <, 6, 8 > J ) <, 3, 4 > J 3) J 4) 1 J 5) 5 J

22 ed. Lab., Mon. Tues. ed. Lab. Mon. Tues (.1) Intoducng Enegy & ok Quz 5 L5: Buoyancy, Ccles & Pendulums (.) Rest Mass,ok by Changng oces tudy Day tudy Day (.18,.19) Intoducng Potental Enegy The Thngs Physcsts & Engnees Do (.) Gavtatonal P.E. & Vsualzng RE 6.a laptop RE 6.b tudy Day tudy Day RE 6.c (last day to dop) RE 6.d Electc and Rest Enegy RE 6.e EP6, H6: Ch 6 P s 58, 59, 91, 99(a-c), 15(a-c) moton s nethe ceated no destoyed, but tanseed va nteactons. Enegy E all d ok

23 Eample. An electon (mass 9e-31 kg) s tavelng at a speed o.95c (so v/c =.95)n an electon acceleato. An electc oce o 1.6e-13 N s appled n the decton o moton whle the electon tavels a dstance o m. e want to detemne the new value o v/c o the electon, usng the enegy pncple. Eample 1: The acat cae Nmtz has a ully loaded mass o kg. It tavels a dstance o m n 3.5 h ( s). hat s the aveage knetc enegy (n joules) o the Nmtz?