1CT 2.1.1You get the strobe timed so anobject appears stationary.What if we speed up the strobe’sfrequency just a little?a) The object still staying stationaryb) The object alternating back andforth between two extremesc) The object moving forwardsd) The object moving backwardse) Can’t really guessCT 2.1.2When the amplitude of an oscillatingobject is doubled, the period becomes:a) twice as bigb) 1/2 as bigc) Stays the samed) 1/4 times as bige) Not enough information to decideWhen the frequency is doubled, the period becomes…CT 2.1.3If I lower the frequency of this tone whathappens to the pitch?a) It decreasesb) It increasesc) It remains the samed) Not enough informationWhat if I make the same sound louder (keeping the same pitch), the frequency…CT 2.1.4A vibration has a frequency of 100cycles/second, what is the period (or theamount of time for one cycle)?a) 100 secb) 1 secc) 10 msecd) 100 msece) None of theseIs this tone audible? If so, is it high or low?2CT 2.1.5You are standing outside playing a recorder*at a steady, perfect “concert A” (that’s 440Hz, i.e. during one second 440compressions of air move outwards).What is the approximate wavelength of thesound wave produced?(Data: the speed of sound is 344 m/s)a) a few mmb) about half a kmc) A little over one meterd) A little under one metere) None of the aboveCT 2.1.6The air warms up by 20o C. It turns out that thisinstrument (like most wind instruments) producessound waves of a particular wavelength.So, changing the temperature will not changethe wavelength of sound waves produced bythis instrument (noticeably.)What will change?a) Frequencyb) Speedc) Bothd) Neithere) ??Speed = wavelength*frequencyv = λ f CT 2.1.7We know that pressure changes (as timegoes by) for sound waves.What changes (as time goes by) for gentlewater waves on a pond?a) The water densityb) The water temperaturec) The water level or heightd) The water molecules’ position in thedirection of wave propagatione) Nothing about water waves vary with timeCT 2.1.8Amplitudetime (sec)1 2Looking at the following waveform, whatis the period?a) 1 secb) 2 secc) 1 m/sd) 2 m/se)Not enough information3CT 2.1.9Looking at that same wave (shown againbelow), what is its speed?a) 1/2 m/sb) 2 m/sc) 5 m/sd) 20 m/se) Not enough informationAmplitudeTime (sec)1 2Now given that λ=10 m what is the speed ofthe wave?The wavelength, λ, is 10 m. What is thespeed of this wave?a) 1 m/sb) 7 m/sc) 10 m/sd) 15 m/se) None of the above/not enough info?CT 2.1.101Time (sec)AmplitudeCT 2.2.1An oscilloscope presents a graphicalrepresentation of:a) Amplitude vs. Positionb) Wavelength vs. Timec) Voltage vs. Positiond) Voltage vs. Timee) Wavelength vs AmplitudeCT 2.2.2What is the difference between the pinkand green lines?a) Frequencyb) Amplitudec) Periodd) Phasee) Something elsetimeAmplitudeYou do not need to know this, but if you arecurious…4CT 2.2.3What is the period of this wave?a) t1b) t2c) Not at all definedd) Not well defined, but t1 is the bestanswere) Not well defined, but t2 is the bestanswert=0t1t2AmptimeCT 2.2.4What is the period?a) t1b) t2c) t2-t1d) t3-t1e) None of the abovet1t2t3Amptime0CT 2.4.1Which of the following is necessary to makean object oscillate?i. A stable equilibriumii. Little or no frictioniii. A disturbancea) i. onlyb) ii. Onlyc) iii. Onlyd) i and iii onlye) all threeGiven the above, will the motion be “Simple HarmonicMotion”?CT 2.4.2(We didn’t really talk about this in class, but ifyou’re curious:) The mass and springshown below are inequilibrium, a brief downward force is appliedto the mass to put the object into oscillation,in what direction is the restoring force?a) Downb) Upc) Zerod) Some other directione) Not enough informationmmequilibriummoving down5CT 2.4.3(We didn’t really talk about this in class, but ifyou’re curious:)Looking at the same spring and massscenario; the spring is stretched andreleased. After a moment, when the massis on its way up, what is the restoring force?a) Downb) Upc) Rightd) Lefte) Some other directionmequilibriummmoving up6CT 2.4.4You are going skydiving. While you are freefalling what is happening to the energy in thesystem?a) Potential energy is being transferred tokinetic energyb) Kinetic energy is being transferred toPotential energyc) The total energy of the system isdecreasingd) The total energy of the system isincreasinge) ??CT 2.4.5Freq. = (constant) * √ (K/m)A mass on a spring oscillates with acertain amplitude and a certainfrequency. If the mass is replacedwith one 4 times heavier, whathappens to the frequency…A doublesB: increases by 4C: halves.D: decreases by 4E: None of these/not sureWhat happens to the period?CT 2.4.6F = (constant) * √ (K/m)A mass on a spring oscillates with acertain amplitude and a certainperiod T. If the mass is doubled, thespring constant of the spring isdoubled, and the amplitude ofmotion is doubled, the period ..A: increasesB: decreasesC: stays the same.D: Not enough information to
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