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> he speed in mi/hr and m/s. (Given: 1.0 m/s = 2.24 mi/hr) E= 4o 43 m. 13 mi/ne | 1 Unit 1 - Wave Basics: Problem Set e KEY Problem 1: \ PAGE b Jerome and Claire are doing the Period of a Pendulum Lab. They observe that a pendulum makes exactly 10 complete back and forth cycles of motion in 21.8 seconds. Determine the period of the pendulum. = 2,185 £=1 M%m o*%wh JJ|.P = & Strong winds can apply a significant enough force to tall skyscrapers to set them into a back-and-forth motion. The amplitudes of these motions are greater at the higher floors and barely observable for the lower floors, It is said that one can even observe the vibrational motion of the Sears Tower in Chicago on a windy day. As the Sears Tower vibrates back and forth, it makes about 8.6 vibrations in 60 seconds. Determine the frequency and the period of vibration of the Sears . flfl mfiMWw =13, 1.% 1& T= %l—b./w m\qlunl\ CJ bs The spin rate of a CD-ROM varies according to the location on the disc from where data is being accessed. When accessing data from the inner cirdes of the disc, the CD can spin at a rate as high as 400 revolutions per minute, Determine the riod (in won“v:amv of the spinning CD. fl“$8 rev oy f FN flfl<\h -, (@@= o15s) cos Like all planets, the planet Venus orbits the Sun in periodic motion and simultaneously spins about its axis. Just as on Earth, the time to make one complete orbit (i.e., the period of orbit) is what defines a year. And the time to make one complete revolution about its axis (i.e., the period of rotation) is what defines a day. The period of orbit for the Earth Is 365.25 days and the period of rotation is 24 hours (1.00 day). But when these same values for Venus are expressed relative to Earth, it is found that Venus has a period of orbit of 225 days and a period of rotation of 243 days. So for Venus inhabitants, a day would last longer than a year! Determine the frequency of orbit and the frequency of rotation (in Hertz) on Venus. Problem 2: Problem 3: Problem 5: Extreme waves along ocean waters, sometimes referred to as fréak waves or rogus waves, are a focus of mugh research and study amoQg scientists. Several merchant ships reports rogue waves which are estimated to be 25 meters high and 26 3»33 loffth Assuming that these waves travel st speeds of 6.5 ..Em_ determine the frequency and the period of these iw(flm W yfi, ?V\Nvgm ’ — Comm) ™ &5 Isynamis are much different than rogue waves. While rogue waves and other waves are generated by winds, tsunamis originate from geological events such as movements of tectonic plates. Tsunamis tend to travel very fast. A tsunami generated off the coast of Chile in 1990 is estimated to have traveled approximately 6200 miles to Hawaii in pm hours. m’ VNCC?_ Shr 2.24 ™/nr : A geological disturbance in California produces seismic waves which are detected in Phoenix, approximately 990 km from the epicenter. If the waves travel 6.3 km/s, determine the time delay between the disturbance and the detection. Problem 6: Problem 7: a="a90 Km s=d L3=910 (4] o Problems: < = [ 3 Km/g - = t wflmfiwb3 ) Microbats use echolocation to navigaté and hunt. They emit pulses of high frequency sound waves which reflect off obstacles and objects in their surroundings. By detecting the time delay betwéen the emitted pulse and the return of the reflected pulse, a bat can determine the location of the object. Determine the time delay between the sending of a pulse and the return of its reflection from an object located 12.5 m away. Approximate the speed of the sound waves as 345 m/s. |\I‘l‘ 2 Za-25m s s =5=9 _26m . t t t=0.07453 Ad.w@ o Sl Logan, Cassie and Abbey are doing the Pulse Speed Lab. Logan and Cassie sta! nd stretch a zinc-coiled snakey between them. Logan introduces a pulse into the snakey at his end. Using atch, Abbey measures that it takes 15.1 seconds for the pulse to travel to Cassie's end and back two times. They then repeat the experiment with a copper-coiled snakey stretched the same distance and find that pulses travel back and forth two times in 16.9 seconds. a. Determine the speed of the pulse in the zinc-coiled snakey. sS= _N.w 2 .\ 8 1 S = _ va 3\% b. Determine the spead of the pulse In the copper-coiled snzkey. ) .\ S 27.2%e.q¢ = 1.6l M/s SmuEQJDINQNM?BL. Problem 9: Problem 10: Sachi is rock'n tp her favorite radio station - 102.3 FM. The station broadcasts radio signals with a frequency of 1.023 x 10° Hz. The radio wave signal travel through the air at a speed of 2.997 x 10°® m/s. Determine the wavelength of these radio waves. Problem 11: A transverse wave is observed to be moving along a lengthy rope. Adjacent Qoflu are gm.n_o..m. xactly six crests are observed to move past a given point along the medium in 9.1 secqnd speed of these waves. W| b Problem 12: E A A marine weather station detects waves which are 9.28 meters long and 1.65 meters high and travel a distance of 50.0 meters in 21.8 seconds. Determine the monoa and Sm frequency of these waves, L c S= Q 3 mlwxfi Problem 13: d S=2, Naw 2.29 = q.28- mu A h.h\lo 25Y Humpback whales are known to produce a collection of elaborate and repeating sounds with frequencies ranging from 20 Hz to 10 kHz. The sound waves travel through water at speeds of approximately 1400 m/s. Determine the wavelengths of the waves at the lower and the upper end of this frequency range. Problem 14: A wave is traveling in a rope. The diagram below represents a snapshot of the rope at a particular instant in time. Determine the number of wavelengths which is equal to the horizontal distance between points ... .. Cand E on the rope. I A .. C and K on the rope, 35\ ... A and ) on the rope. 4 ) ... B and F on the rope. .5\ .. D and H on the rope. 2 ... E and I on the rope. ,QM\/ ~sapgw Problem 15 (challenge): Ryan and Carson attended their church's youth retreat at Camp Paradise this past fall. On Saturday afternoon they took a walk out to the harbor and watched Incoming waves from Lake Michigan rock the boating piecs up and down. Ryan and Carson observed that {§e piers made a complete up and down vibration cycle In 6.6 seconds) The piers were positioned a distance of 24 :..m«mamww When one pier was at 3 high position, the neighboring pier was at a iow position and there was exactlyBRe wave crest between them. Determine the wavelength, frequenty and speed of the waves. T= b.bs \\IJ |\\\\$/// fiup.lur //\l\\l\\@ (F-= o_.uN Hz _ - Ql NL.B H\/fl 1L.SA= 2m = 1bs OIS { Naltinn