Mak answes in spaces 31-43 on the answe sheet PHYSICS 1 Summe 005 EXAM 3: July 5 005 9:50pm 10:50pm Name (pinted): ID Numbe: Section Numbe: INSTRUCTIONS: Some questions ae one point, othes ae two points, as maked. Answe all questions. All questions ae multiple choice. Questions 31-36 ae 1 point, 37-43 ae points. Befoe tuning ove this page, put away all mateials ecept fo pens, pencils, eases, ules, you calculato and aid sheet. An aid sheet is one two sided 8½ 11 page of notes pepaed by the student. Note also fomula sheets pages.. "In geneal, any calculato, including calculatos that pefom gaphing numeical analysis functions, is pemitted. Electonic devices that can stoe lage amounts of tet, data o equations ae NOT pemitted." If you ae unsue whethe o not you calculato is allowed fo the eam ask you TA. Eamples of allowed calculatos: Teas Instuments TI-30XII/83/83+/89, 9+ Casio FX115/50HCS/60/7400G/FX7400GPlus/FX9750 Shap EL9900C. Eamples of electonic devices that ae not pemitted: Any laptop, palmtop, pocket compute, PDA o e-book eade. In making the multiple choice bubble sheet use a numbe pencil. Do NOT use ink. If you did not bing a pencil, ask fo one. Fill in you last name, middle initial, and fist name. You ID is the middle 9 digits on you ISU cad. Special codes K to L ae you ecitation section, fo the Honos section please encode you section numbe as follows: H1 0; H 13 and H3 31. If you need to change any enty, you must completely ease you pevious enty. Also, cicle you answes on this eam. Befoe handing in you eam, be sue that you answes on you bubble sheet ae what you intend them to be. It is stongly suggested that you cicle you choices on the question sheet. You may also copy down you answes on the ecod sheet (page 1) and take this page with you fo compaison with the answe key to be posted late. When you ae finished with the eam, place all eam mateials, including the bubble sheet, and the eam itself, in you folde and etun the folde to youecitation instucto. No cell phone calls allowed. Eithe tun off you cell phone o leave it at home. Anyone answeing a cell phone must hand in thei wok; thei eam is ove. Thee ae 13 questions on this eam labeled 31-43. Mak answes in spaces 31-43 on the answe sheet. BEST OF LUCK! 1
31) (1 point) A pendulum in a science museum is designed to have a peiod of 5 s. The length of the pendulum is a) 6. m b) 7.8 m c) 1.4 m d) 15.6 m e) none of the above 3) (1 point) A thin shell of chage has a adius R and contains a total chage Q. What is the electic field inside the shell at a point a distance fom the cente of the shell (<R)? a) E= kq/ b) E= kq/r c) E=0 d) E= kq/ e) can not be detemined 33) (1 point) The units of electic flu (Φ E ) ae a) Nm b) N/C c) Cm d) Cm /N e) Nm /C 34) (1 point) Conside a chage Q enclosed within a spheical Gaussian suface of adius R. Anothe chage 3Q is outside the sphee, as shown in the figue. What is the flu though the sphee? a) Q/ε 0 b) - Q/ε 0 c) Q/ε 0 d) -Q/ε 0 o -Q e) none of the above o 3Q
35) (1 point) A sping is oscillating with amplitude a, aound a cental position =0. The gaph of position vs time is dawn below. Whee is the speed maimum in simple hamonic motion? a) A b) B c) C d) D e) E 36) (1 point) A positive chage +Q is shown in the figue. At which of the points A, B C, D, E is the magnitude of the field a maimum? A) B) C) D) E) A E B +Q C D 3
37) ( points) A hamonic oscillato is made by using a 0.6 kg block attached to an ideal sping of foce constant 150 N/m. The peiod of oscillation is a) 15.8 s b).5 s c) 0.8 s d) 0.4 s e) 0.06 s 38) ( points) A machine pat is undegoing simple hamonic motion with a fequency of 10 Hz and an amplitude of 1.5 cm. How long does it take the pat to go fom the cental position =0 to the position =-1.5 cm? a) 1s b) 0.16 s c) 0.1 s d) 0.05 s e) 0.05 s 39) ( points) A new planet has a adius of twice the Eath s adius but only twice the Eath s mass. If the acceleation due to gavity on Eath is g, then the acceleation due to gavity at the new planet s suface is a) g/4 b) g/ c) g d) g e) 4g 40) ( points) Two satellites ae in cicula obit aound the Eath. The fist has a adius of and the second at a adius of 3, measued fom the Eath s cente. The atio of the peiods of the satellites is a) 1:1 b) 1:3 c) 1:5. d)1:9 e) 1:7 4
41) ( points) Thee chages qa=+4 µc, qb=+6 µc and qc=-µc ae aanged along a staight line. Chage b is between a and c with the distances shown in the figue. A) What is magnitude and diection of the net foce on chage qb. ( i is the unit vecto along the ais) ^ qa qb qc 0.1 m 0.1 m ^ A) 3 i N ^ B) -3 i N ^ C) +11 i N ^ D) 11 i N E) 0 N 4) ( points) An electon is pojected with a speed of 10 6 m/s into the unifom field between the paallel plates shown in the figue. The electon deflects upwads by 1 cm, afte taveling a distance of cm along the plates. The electic field between the plates is a) 1.110 5 N/C downwad b) 570 N/C downwad c) 1140 N/C upwad d) 1140 N/C downwad e) none of the above 5
43) ( points) The electic field at a pependicula distance of 18mm fom the middle of a long thin unifomly chaged od is measued to be 3.510 4 N/C and diected away fom the od. What is the linea chage density of the od? -5 a) 3.510 C/m b) 6.10-7 C/m c) 3.510-8 C/m d) 7 10-8 C/m e) none of the above 6
Fomula Sheet fo Eam 1 1. Physical Constants (numeical value used to deive answes in eam): 1.1) Acceleation of gavity on Eath s Suface: g=9.8m/s² 1.) Radius of Eath: R eath =6.38 10 6 m 1.3) Mass of Poton: mp=1.67 10-7 kg 3. Vectos 3.1) Dot Poduct: A B = A B + A B + A B = A B cosθ whee θ is the angle between A and B. 3.) Components: A = A iˆ + A ˆ y j + Azkˆ 3.3) Magnitude: V = V = V + V + V = V V 5. One Dimensional Motion 5.1) Aveage Velocity: v = / t 5.) Instantaneous Velocity: v = d / dt 5.3) Fo Constant Acceleation only: y y y z t z v = v v 0 z 0 0 = v + v 0 0 = a = 1 + a t + ( v 1 ( t a + v t 0 0 ) ). Calculus n+ 1 d n n 1 n d = n d.1) = n + 1 sin = cos cos = sin d d 4. Algeba 4.1) The solutions to a + b + c = 0 6. Foces 6.1) Newton s Second: F = ma 6.) Newton s Thid: F AB = FBA 6.) Kinetic Fiction: f = N d d ae = ( b b ac ) 1 a ± 4 k µ k s µ s 6.4) Static Fiction: f N 6.5) Centipetal Foce: mv F = R 7. Thee Dimensional Motion 7.1) Position Vecto: = iˆ + yj ˆ + zkˆ d d d 7.) Velocity and Acceleation: v = dt a = dt v = dt v = v0 + at 1 = 0 + v0t + at 7.3) Constant Acceleation only: v v0 = a ( 0 ) 0 1 = ( v + v0 ) t 7.4) Cicula Motion: f = 1 / T ω = πf v = Rω 7.4a) Angula Velocity: ω = d θ / dt 7.5) Centipetal Acceleation: = Rω = v / R = (4π R) / T a ad 7
Fomula Sheet fo Eam 8. Kinetic Enegy and Wok 8.1) Linea Motion: K = 1 mv 1 8.) Rotational Motion: K ot = Iω 8.3) Wok by a constant foce W = F s = Fscosθ 8.4) Wok done by a vaiable foce in 1 dim: W = 1 F d P P 8.5) Wok in 3D: W = F dl = F cosφ dl P1 P1 8.6) Powe: P=dW/dt P = F v 9. Potential Enegy 9.1) Gavitational: U gav =mgy 9.) Sping: U sping =k²/ du 9.3) Foce fom potential in 1D: F ( ) = d 9.4) Consevative foce fom potential in 3d: a 10. Momentum and Impulse 10.1) Momentum: p = dp mv F = dt t 10.) Impulse: J = F dt = p p t1 net 10.3) Cente of mass position: M tot cm = mi i 10.4) Cente of mass velocity: M totvcm = pi 10.5) Cente of mass acceleation: M totacm = Fi = Fetenal 11. Collisions 11.1) 1-dimensional totally inelastic collision: v 1 f = v f = vcm v1 f = vcm v1 i 11.) 1-dimensional elastic collision: v = v v 11.3) 3-dimensional totally inelastic collision: v 1 f = v f = vcm 1 f cm i 1. Rotation dθ 1.1) Angula velocity ω = dt dω 1.) Angula Acceleation α = dt 1.3) Cicula motion: a ad = Rω ; a tan = α. 1.4) Moment of Inetia: I = m i R i 1.5) Paallel Ais Thm.: I P = I cm + Md 1.6) Toque: τ = F 13. Angula Momentum 13.1) Fo Paticle L = p 13.) Foigid body L = I ω 13.3) Relation to toque τ = dl dt 14. Static Equilibium 14.1) Condition fo static equilibium: net τ 0 ; F = 0 = net 8
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Fomula Sheet fo Eam 3 15. Physical Constants 15.1) Gavitational Constant G=6.673 10 11 Nm²/kg² 9 15.) Coulomb s Constant k E = 8.9876 10 Nm = 1 / 4 πε 0 1 15.3) Pemeability of vacuum ε0 = 8.854 10 C /( Nm ) 15.4) Magnitude of electon chage e=1.6010-19 C 31 15.5) Mass of electon m e = 9.11 10 kg C 16. Gavity m1m 16.1) Newton s Law of Gavitational Attaction: F = G m1m 16.) Gavitational Potential U = G M 16.3) Acceleation of gavity g = G 16.4) Escape velocity v = gr = GM R e / 16.5) Gavitational acceleation at the Eath s suface g=9.8 m/s 16.6) Obital motion centipetal foce = mv /R =GMm/R obital speed v = v = GM / R 18. Hamonic Oscillation 18.1) Peiod/fequency: f = 1/ T ω = π f = π / T 18.) Foce law fo hamonic motion: F = k 18.3) Angula fequency of oscillato: ω = k / m 18.4) Solution to oscillato = Acos( ω t + φ) 18.5) Simple pendulum ω = g / L T = π L / g 18.6) Physical Pendulum ω = mgd / I 17. Keple s Laws 17.1) Each planet moves in an elliptical obit with the sun at one focus of the ellipse. 17.) A line fom the sun to a given planet sweeps out equal aeas in equal times. Equivalently, the angula momentum of a planet about the sun emains constant. 17.3) The peiods of the planets ae popotional to the 3/ powe of the semi-mano ais lengths of the obit. If a is the length of the semi-majo ais, 3 / πa T =. Gm sun 10
19. Coulombs Law etc. 19.1) Coulomb s Law: F = keq1 q / 19.) Electic Field fom chage E = k Qˆ E / 19.3) Foce eeted by an electic field: F = qe 0. Gauss s Law 0.0) Geneal definition of electic flu : Φ = E cos φ da = E da = E da E 0.1) Gauss s Law Φ E = q enclosed /ε0 0.) Inside a conducto: E=0; ρ=0 0.3) Electic Field nea a chaged sheet: E = σ /( ε 0) 1. Vaious Fields and Potentials Case Electic Field Magnitude Potential Point Chage Q Line chage, chage pe unit length λ Chaged sheet, chage pe unit aea σ Q E = 4πε 0 E = λ πε 0 E = σ ε 0 V Q = 4πε 0 11
Recod Sheet You may fill in this sheet with you choices, detach it and take it with you afte the eam fo compaison with the posted answes 31 41 3 4 33 43 34 35 36 37 38 39 40 1
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