\Jo/ fy B > > i F lt ~ fu-j"!0 - f1v- N '" 12.5 s E s. . f, :; N - Wlj + l=~'1-{1 :> 0 ---'

Transcription

1 Final Exam Review Practice Exam Leader: Course: Matt T --=--=-"'-'--'' Physics ' Supplemental Instruction Instructor: WhisnantIHo Iowa State University Date: 5/5/13 1. Topics: Relative Motion A bird flies across a SO.O-mwide canyon that runs north-south (see sketch). The bird travels at a speed of 5.00 mls with respect to the air. There is a wind blowing from the north to the south with a speed of 3.00 m/s. How long will the bird take to cross the canyon if it wants to travel straight across, from point A to point B? ~ ~...> A s B s C s E s \Jo/ fy -t \/"'/(; - V~/0 > > N + 'I ~ S.ro...--;;;- :: ~ - 5' A I B 2. Topics: Newton's Laws, I-D Kinematics, Friction A crate of mass In = 51.0 kg is pulled in a straight line along a horizontal floor at constant speed l' = rn/s. An applied force F is exerted on the crate at an upward angle e = 45.0' to the horizontal as shown in the figure. Gravity is acting downward on the crate. The coefficient of kinetic friction of the crate with the floor is The magnitude of the applied force is F = N. (Hint: consider the )~ component of F when calculating the normal force of the floor on the crate) A ~ D. E f, :; N - Wlj + l=~'1-{1 :> 0 () H -..." ri;;" n,j - hkd tv') i F lt ~ fu-j"!0 - f1v- N '" 0 f tojil ~.J1\:,.r ~ I- (WI) - Fl71-DJ ~ f" A.,'r'I1j ~ ~ "2-D2- N ~.rt>tmio- t-l1 e Supplemental Instruction 1060 Hixson-Lied Student Success Center.: :. y F e ,~-~-~;;>...() _fc.9). --+) V

2 3. Topics: 2-D Kinematics, Constant Acceleration A cannon ball is launched hcrizontally off a cliff of height h = 11.0 m above the ground with speed VQ = 40.0 mls as shown in the figure. The cannon ball goes a horizontal distance D = m before hitting h the ground. ignore any influence of air friction. - Vo '. A. 20 B. 40 e 60 D. 80 E. 100 D 4. Topics: Rotational Motion, Conservation of Angular Momentum, Moment ofinertia A track is mounted on a large wheel of mass M = 2.0 kg and radius R = 0.5 Ill, which is free to turn with negligible friction about a vertical axis through its center. A toy train of mass m = 1.0 kg is placed on the track and, with the system initially at rest, the train's electrical power is turned on. The train reaches a speed of 0.15 rn/s with respect to the track. What is the angular speed of the wheel? (Treat the wheel as a hoop, and neglect the mass of the spokes and hub.) ~O.IO radls B) 0.13 radls C) 0.16 radls D) 0.20 rad/s E) 0.25 radls

3 5. Topics: Statics (Newton's Second Law and/or Torque) Two point masses m, = 5.00 kg and "', = kg are balanced on a massless beam (the distances L, and L: jn the figure are not to scale). If L, = 6.00 m. lhenl,= A. 2 C. 3 D. 4 E. 5 _ffi. 1.'[ -:;0 ""'0" ; ~l"'-t ~.t.... ), l l.... 'Z. -:: I' massless bea 6. Topic: Conservation of Mechanical Energy, Energy Diagrams The figure below represents potential energy as a function of position on the x axis o -20 rrr I o \, I \ j / \ I \ 1/ \ / \ / \ / f\/ x (m) j j l I The force associated to this potential is the only force acting on a particle with mass 1.00 kg. When the particle is at x = 6.00 m, its velocity is v = m/s. What is the maximum kinetic energy that this particle will achieve? A. 10.0J B J C J D J (S)42.5 J lalxzb..,) -:. PE+~~ 'l. " o + 1LI ~, ).l~s' ~ ) _ "'{ _",) fl.+-,; I 'Z..r- :s "I~'~ oj ~TV r ) t-1~...~ - J 0 ) c.t 'I ~ '2.~-... Ii IN-li. ~)' lao",l r... ):;. -~ot"' =.,2 F) /e-e-;.~o Jt\2. rs

4 7. Topic: Doppler Effect An emergency vehicle is approaching you with a speed of 35 mls while you stand on the sidewalk. Y 011 bear a sound wave of frequency 850 Hz from the siren of the emergency vehicle. What frequency would you hear if the emergency vehicle stood at rest next to you? j 763 Hz b. 784Hz c. 804 Hz d. 878 Hz e. 910 Hz 8. Topic: Pendulums, Periodic Motion Two simple pendulums are constructed with very light strings. Pendulum 1 has a string of length L and a bob of mass m. Pendulum 2 has a string of length 2L and bob of mass 2m. Let T 1 and T2 be the periods of these pendulums for small oscillations. What is the ratio between these periods, TJT2? A. B D..fi. E. 2 T T=- 9. Topic: Harmonic Motion, Standing Waves A stretched string of length 1.11 m has both ends fixed in position. The tension in the string is 500 N. The 3'" harmonic transverse standing wave on the string has a frequency of 550 Hz. The linear mass density of the string is g/m. A. 1 E. 5

5 10. Topic: Harmonic Motion The figure below is a "snapshot" of a wave at one pointin time. The frequency of the wave is 120 Hz. What is the speed of the wave? A) 10.mls 12m1S ) 4m1s ~ ) 36 m1s \~" \10 \h Y(mr-')..., E) 48 mls ~:; H::. b 20' I~o \ t"1 ~ l'"{ o 010 x(m) 0" Topic: Volumetric Thermal Expansion (for AI, alpha = 2.4e-5 11K) An aluminum solid sphere has a radius of3.00 ernat room temperature (300K). To which temperature should we heat the sphere if its volume is to increase by 0.1%? DIJ- J."\ \ K ~..L ~ If -Ii, b. 328 K 1/. }~ c. 342K T'+~ = d. 355 K ~ 3 q e. 371 K l>\f ~ ~. \l c> '~T ~ ~') 0( 12. Topics: Thermodynamics, Phase Changes (assume tea has the same properties as water) Some ice at O'C is placed in a thermos that contains liters of tea at 70.0 C. The ice melts and the system reaches equilibrium at a final temperature of 40.0"C. How much ice was placed in the tea? ill \ l+ 1-' VI-" +q.jj -e, ~~ \Jl ',(..t!me f \... 'tl 125 g 0.\ ~ \.:1' "-<4 Q ( ; c..e. \J" (,00 ltd) B 188 g L. C ( C: 198 g -"Iic ~. f 1 t ,;~ H~o' 1l1'::.-...f... ~ ~D' 0r D. 375 g ~...,fc#1 [/:Ito' DI E. 452 g """il..e ~f,l1l0 t~e'(~~ollr :> (J. s: \l~. Y Iq 0 L.1,. s" \<... J 3" fj... 31,/(}oo 1<., t- Y/IfO' SD Ie- =- o 12r ~J

6 Topics: Ideal Gas Law, Kinetic Model of Gases, Root-mean-square Velocity Neon gas is a monatomic ideal gas with an atomic weight of 20.2 g1mol. The rrns speed of a neon atom in neon gas at a temperature of 292 K is mls. A Topics: First Law of Thermodynamics, Thermodynamics Processes A gas goes through the thermodynamic cycle A ~ B ~ C ~ A shown below. Let W, Q and t.u be the total work done by the gas, heat absorbed by the gas and change in internal energy of the gas in each cycle. Which of the following is true? x W > 0; Q > 0; lj.u > 0 (9 W > 0; Q > 0; lj.u = 0 ~ W = 0; Q < 0; lj.u < 0 D. W < 0; Q > 0; lj.u = 0 E. W < 0; Q < 0; lj.u = 0 ca - 0 j)v,,\~\{ - W/tg >\,..)13c.. v-j ~ c,,\e ') 0 p A :~--~B C v 17. Topics: Thermodynamics Processes, Work An ideal gas goes around one complete cycle in a clockwise direction on a P: V diagram as shown in the figure, where the initial point I on the cycle is the same as the final point 2. The net work done by the gas during the cycle is B. -8 C. 12 D. -12 E. 18 IrJ = AlAe. = L w ~ Lj L' 2.. Ol~ :;~l'rtv-

7 Topics: Carnot Cycle, Second Law of Thermodynarnics A Carnot heat engine that operates between a low temperature T L = 300 K and a high temperature T H = K has an efficiency of 50% for conversion of heat into work. A.400 B. D. 700 E. 800 '1<- (- ~oo i~ I-Tt-I' ":: f" ~ - Ttl 19. Topics: Carnot Cycle, Second Law of Thermodynarnics A heat engine operating between 40 C and 380 C has an efficiency 60% of that of a Carnot engine operating between the same temperatures. If the engine absorbs heat at a rate of 60 kw, at what rate does it exhaust beat? )36kW 41 kw ~ C 57kW D)60kW E) 66 kw t. _ 0." ( 1- ;2..")11'1 ) Ii. -:. (). b l-(o; ""t" - 2-??t10C> = o ~ (2 ~ ~ (f-s,p; QH ~ v.> +- Q c. Q" "- o:m'~11 -/-Qc.. (f/t(i-o.}p.) 20. Topics: Carnol Cycle, Second Law of Thermodynamics A) 224 K 8) 310 K S<) 340 K Q) 378 K E)412K... Ql: Qt~ 6o/W(r -0 SId.:. 'i (l.'lf! (..vj 77) A Carnot engine whose high-temperature reservoir is at 620 K takes in 550 J of heat at this temperature in each cycle and gives up 335 J to the lowtemperature reservoir. What is the temperature of the low-temperature reservoir?,,\ _, t I\:) e : ~ _ QH- Qt \J{I~ -\V c. c-- If - ~ =-/- H :>'j"d- H-C _ l _r'- ssv ",0 -b~o( j)-o-s\si')~t(... rro QI1 21. Topics: Entropy, Phase Changes When 1.00 kg of ice at its freezing point of 0 'C is melted, the entropy of the resulting liquid water at 0 'C is. the entropy of the icc at 0 'c. A. smaller than ~arger than =-...E... [:I C,(,e T.,(."- C. the same as s~ T Q - r ljs;-:>o I,'~ io/ phllit hldr«cj a,- t116rc (,~oh' (JiJ'l9r ~J ~II ew~ f1 ~ b~{t,) J'lll,J