Question

ON THIS PAGE. SHOW WORK ON THE OPPOSITE PAGE VERS ON 20) Riding The Waves lculate the missing quantity. Hint: 1 Hz= 1 per second (= 1 sec ) = 3,600 /hour) Earthquake!! : An earthquake in Calexico, CA was felt in San Diego (210km distant) 28 seconds. The quake swayed houses @ twice per second = 2Hz. (1) The wave velocity was (2) The earthquake WAVELENGTH in km was: v= km/sec. 2= B) Thunder: After a lightning flash, you hear thunder (at a LOW pitch) &measure the sound wavelength = 20 meters Hint: Assume Ysound ~ 340 m/sec. The thunder frequency was: Hz The thunder period was: P= seconds C) Equipment: Find the requested quantities. (1) X-ray machine photons are 0.1 nm wavelength. Find the frequency f = (2) An Ultrasound machine emits sound waves at 80,000 Hz. Find the wavelength if Vsound - 340 m/sec. 2= (3) SCC Wi-Fi links have a frequency of 2.4 GHz (2,400MHz). 2- _ meters ANSWERS ON THIS PAGE. SHOW WORK ON THE OPPOSITE PAGE A5. (20) The Winds of Change. The NS Tutor Center door measures 2.4m high & 0.92m wide. When the air conditioner is on, the door will NOT close by itself because of overpressure (inside pressure greater than normal atmospheric pressure). Adam used a stockroom scale and found 100N force is needed to close the door. 1) (9) Find the torque exerted on the door hinge. Pa 2) (9) Find the overpressure in Pascals. 3) (2) Find the overpressure in Atmospheres (atm) ANSWERS ON THIS PAGE. SHOW WORK ON THE OPPOSITE PAGE _Hz BONUS QUESTION FOR 10 POINTS): B1. (10) As shown in the "Light" PPT lecture, Olaus Romer (ca. 1690) investigated the large time variations between Actual vs. Predicted times for the eclipses of Jupiter's moons. He discovered that light speed is fast but NOT infinite with the current value = 300.000 km/sec. Earth orbits the Sun at 150,000,000 (1.5 x 10 km away, while Jupiter is 5.2 times the Earth's distance from the Sun. Sometimes, Earth is on the same side of the Sun as Jupiter, or on the opposite side of the Sun, or in between For 10 points, find the maximum At i.e., the time difference error = [observed - predicted]) for eclipses of Jupiter's moons caused by the finite speed of light. sec. ANSWERS ON THIS PAGE. SHOW WORK ON THE OPPOSITE PAGE

Answer 1

A ) A) anth quake f a Hz EOT v= 28 2) 2 3 750 m 4s 2 TRnd 3o mls 20 7 H 2o T O O59 Ssec Ezuipment nm V Hz 3 r108 2) f 80, o 0 6 V 2 34o 4. 25xom Ans 340 60,000 H2 3) 2 3a 1o2 0.125m ther uns ueshien PLemse post