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Across 4. The material called ______ is needed for sound waves to travel through 9. Speed= _____ x wavelength 12. Sound waves are ____ waves 13. Speed of sound travels the fastest through ____ 16. Sound waves are caused by V_____s 17. X-rays can cause _____ to living cells 18. The theory that explains the effects of waves is called a _____ theory 19. The number of waves passing any point per second 20. The maximum distance a point moves from its rest position when a wave passes 21. Sound cannot travel through a ...

Down 1. ___ is when the waves are reflected from the surface at the same angle as they strike in 2. Distance=______ x speed 3. Measures the depth of water under a boat 5. Frequency is measured in ... 6. Sound waves can travel trough Solids, Gases and ... 7. S_______ waves are caused by vibrations 8. Device for viewing oscillations by a display on the screen of a cathode ray tube. 10. A type of sound having an ultrasonic frequency, can be used in medical imaging 11. The amplitude of a wave determines how ____ it is 14. The distance between any point on a wave and the equivalent point on the next 15. High frequency means the ___ is also high 18. Ultrasound can be used to scan a pregnant woman's ...