A 5.00-m, 0.732-kg wire is used to support two uniform 235-N posts of equal length (Fig. P15.55). Assume that the wire is essentially horizontal and that the speed of sound is 344 m>s. A strong wind is blowing, causing the wire to vibrate in its 5th overtone. What are the frequency and wavelength of the sound this wire produces?
66. What is the minimum number of slits required in a diffraction grating to just resolve light with wavelengths of 471.0nm and 471.6nm A. 99 B. 197 C. 393 D. 786 E. 1179 ans: C 67. X rays are: A. electromagnetic waves B. negatively charged ions C. rapidly moving electrons D. rapidly moving protons E. rapidly moving neutrons ans: A 68. Bragg’s law for x-ray diffraction is 2dsinθ = mλ, where θ is the angle between the incident beam and: A. a reflecting plane of atoms B. the normal to a reflecting plane of atoms C. the scattered beam D. the normal to the scattered beam E. the refracted beam ans: A 69. Bragg’s law for x-ray diffraction is 2dsinθ = mλ, where the quantity d is: A. th