e) famy fzack Amy 14. An original standing wave is shown. Which of the modes below has twice the frequency? Original standing wave boos possoood 15. When a tuning fork of unknown frequency is struck together with a 496 Hz tuning fork, a beat frequency of 3 Hz results. When it is played together with a 484 Hz tuning fork, a beat frequency of 9 Hz results. The frequency of the unknown tuning fork is: 499 HZ b) 490 Hz ) 475 Hz d) 493 Hz e) 487 Hz 16. A fat string and a skinny string are connected and pulled taut, and a wave is set up in the strings. When the wave crosses the boundary from string 1 (thin) to string 2 (thick), the wave speed: a) increases. b) decreases. c) stays the same