Start Quiz Click the correct answer A family ice show is held at an enclosed arena. The skaters perform to music with level 80.0 dB. This is too loud for your baby, who yells at 75.0 dB. (a) What total sound intensity engulfs you? (b) What is the combined sound level? 1 / 10 1 1.32 x 10-4 W/m2 , 81,2 dB 2 1.42 x 10-4 W/m2 , 80,2 dB 3 1.52 x 10-4 W/m2 , 81,2 dB 4 1.62 x 10-4 W/m2 , 83,2 dB Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer A loudspeaker is placed between two observers who are 110 m apart, along the line connecting them. If one observer records a sound level of 60.0 dB and the other records a sound level of 80.0 dB, how far is the speaker from each observer? 2 / 10 1 R2 = 20 m and R1 = 90 m 2 R2 = 10 m and R1 = 100 m 3 R2 = 5 m and R1 = 105 m 4 R2 = 1 m and R1 = 109 m Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer Two small speakers emit sound waves of different frequencies. Speaker A has an output of 1.00 mW , and speaker B has an output of 1.50 mW . Determine the sound level (in dB) at point C if (a) only speaker A emits sound, (b) only speaker B emits sound, and (c) both speakers emit sound. 3 / 10 1 68 dB ; 67.8 dB ; 69.6 dB 2 65 dB ; 68.8 dB ; 69.6 dB 3 65 dB ; 67.8 dB ; 69.6 dB 4 65 dB ; 67.8 dB ; 70.6 dB Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer A tuning fork vibrating at 512 Hz falls from rest and accelerates at 9.80 m/s2. How far below the point of release is the tuning fork when waves of frequency 485 Hz reach the release point? Take the speed of sound in air to be 340 m/s . 4 / 10 1 23.3 m 2 22.3 m 3 20.3 m 4 19.3 m Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer A string with a mass of 8.00 g and a length of 5.00 m has one end attached to a wall; the other end is draped over a pulley and attached to a hanging object with a mass of 4.00 kg. If the string is plucked, what is the fundamental frequency of vibration? 5 / 10 1 15.7 Hz 2 17.7 Hz 3 18.7 Hz 4 16.7 Hz Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer If two adjacent natural frequencies of an organ pipe are determined to be 550 Hz and 650 Hz, calculate the fundamental frequency and length of this pipe. (Use v =340 m/s.) 6 / 10 1 60 Hz ; 1.7 m 2 50 Hz ; 1.7 m 3 50 Hz ; 1.8 m 4 60 Hz ; 2.7 m Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer A student holds a tuning fork oscillating at 256 Hz. He walks toward a wall at a constant speed of 1.33 m/s. (a) What beat frequency does he observe between the tuning fork and its echo? (b) How fast must he walk away from the wall to observe a beat frequency of 5.00 Hz? 7 / 10 1 3.99 Hz ; 4.38 m/s 2 2.99 Hz ; 3.38 m/s 3 1.99 Hz ; 3.38 m/s 4 0.99 Hz ; 3.48 m/s Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer Light with wavelength 442 nm passes through a double-slit system that has a slit separation d = 0.400 mm. Determine how far away a screen must be placed in order that a dark fringe appear directly opposite both slits, with just one bright fringe between them. 8 / 10 1 46.2 cm 2 50.2 cm 3 40.2 cm 4 36.2 cm Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer White light is spread out into its spectral components by a diffraction grating. If the grating has 2 000 grooves per centimeter, at what angle does red light of wavelength 640 nm appear in first order? 9 / 10 1 7.350 2 7.450 3 8.350 4 9.350 Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Click the correct answer Three polarizing disks whose planes are parallel are centered on a common axis. The direction of the transmission axis in each case is shown in the figure below relative to the common vertical direction. A plane-polarized beam of light with E0 parallel to the vertical reference direction is incident from the left on the first disk with intensity Ii =10.0 W/m2. Calculate the transmitted intensity If when (a) θ1=20.0°, θ2 =40.0°, and θ3 = 60.0° ! 10 / 10 1 6.89 W/m2 2 7.89 W/m2 3 8.89 W/m2 4 9.89 W/m2 Next Question You are wrong You are wrong Try Again Next Question You are correct Next Question Total Questions Score per Question Correct Answer Wrong Answer Total Score