SOUND AND LIGHT

1. What is the speed of a wave that has a wavelength of 2 m and a frequency of 1.5 Hz? 3 m 1.33 m 0.75 m 6 m 2. Calculate the frequency of a wave that is traveling at a speed of 3.0 m and has a wavelength of 1.2 m. 3.6 Hz 0.4 Hz 2.5 Hz 1.8 Hz 3. The speed of sound in a metal is 1000 m What is the wavelength if the frequency is 2 kHz? 500 m 50 m 5 m 0.5 m 4. The speed of sound is 346 m If a sound wave travels at a frequency of 55 Hz, what would its wavelength be? 0.16 m 16 m 6.3 m 63 m 5. A wave has a frequency of 1.5 Hz. What is the period? 0.33 s 0.5 s 0.67 s 0.75 s 6. What two factors determine the rate at which sound travels through a medium? stiffness and density stiffness and permeability density and viscosity temperature and density 7. Which of the following statements is true? The stiffer the medium, the faster sound travels through it. The stiffer the medium, the slower sound travels through it. Stiffness doesn't affect the speed of sound. none f of the above 8. Which of the following statements is true? The denser the medium, the faster sound travels through it. The denser the medium, the slower sound travels through it. The density of the medium doesn't have anything to do with the speed of sound. none of the above 9. What formula gives the speed of sound in terms of stiffness and density? 10. How do physicsts measure the stiffness of a material? by its density by its bulk modulus by Young;s modulus none of the above 11. Stiff materials like metals have _ bulk modulus. low average high negligible (very very small) 12. What is the speed of sound in iron relative to the speed of sound in air? 14 times faster 14 times slower 1 times faster 1 times slower 13. The bulk modulus of elasticity of air is 1.41x105 N and its mass density is 1.29 kg Calculate the speed of sound waves in air. 331 m 331 km 331 cm 109,561 m 13. What happens to the density of air when it is heated? it increases it decreases it doesn't change it becomes zero 14. Why does sound travel faster in hot air? because it is less dense because it is denser because it is heavier none of the above 15. Calculate the speed of sound in air at 25oC. The molar mass of air is 28.97x10-3 kg The molar heat ratio is 1.4. 100.22 m 331.7 m 58.91 m 292.53 m