Mr Simnett | For all your Physics and Mathematics needs…



Sound and Waves Review Sheet1.??????Often, when you look very closely at a clear pane of glass, you can see a faint reflection of yourself even though the glass is transparent. Explain why this occurs.2.??????State the type of vibration that occurs in each of the following:(a)?????the spring in a pogo stick as a child bounces up and down on it(b)?????a tree swaying in the wind(c)?????the rotating masses on an anniversary clock3.??????Give some examples of transverse vibrations.4.??????A water wave travels from shallow water (slower medium) into deeper water (faster medium). What happens to the wavelength and frequency of the water wave?5.??????Draw a scale diagram of a standing wave with five nodes, created using a rope that is 25 m long and is fixed at both ends. What is the wavelength of the wave?6.??????Noise cancellation headphones are used by pilots to protect their hearing and allow for better communication. Explain briefly how these headphones work.7.??????The engine of a Grand Prix race car sounds different as it approaches you than when it is moving away from you. Explain why.8.?????Discuss the following statement: "If a tree falls in the forest and no one is there to hear it, it makes no sound."9.?????Explain how the tines of a tuning fork create sound waves.10.?????Long ago, soldiers would place their ears on the ground to give them advance warning of an enemy's approach by listening for the footsteps of the enemy's horses. Why did this provide the soldiers with an advanced warning?11.?????Calculate the period and frequency of a pendulum that completes 150 vibrations in 1.5 min.12.?????A sound wave with a frequency of 1.25 ? 104 Hz travels at 344 m/s. What is its wavelength?13.?????A wave on a coiled spring travels at 6.2 m/s with successive crests separated by a distance of 1.25 m. What is the period of the waves?14.?????A standing wave is generated in a string so that 3 loops are present. The length of the string is 15 m and the frequency of the source is 2.5 Hz.(a)?????Find the wavelength of the waves.(b)?????Find is the speed of the waves in the string.15.?????You are standing 2.5 ? 102 m from a cliff wall and you clap your hands. The echo of your clap returns 1.45 s after you clap your hands. What is the speed of sound in the air?16.?????A student performs a lab using an ultrasonic probe to measure the distance to a wall located some distance away. If the air temperature is 25?C and the sound signal returns 3.0 s after it was sent, how far away is the wall?17.?????What is the speed of sound on a warm, summer day when the temperature is 30?C?18.?????During a fireworks demonstration, an observer measures the time difference between the flash of light emitted and the sound heard from the explosion to be 1.50 s. If the air temperature is 20?C, how far away is the fireworks explosion from the observer? (Assume that the flash is seen instantly.)19.?????The tine of a tuning fork makes 20 vibrations in 0.50 s. If the speed of sound is 350 m/s, what is the wavelength of the sound wave created?20.?????A tuning fork with a frequency of 512 Hz is struck at the same time as a guitar string. If 24 beats are heard in 6.0 s, find the possible frequency or frequencies of the guitar string.21.?????A train with a blowing whistle that has a frequency of 550 Hz is travelling at a speed of 80 km/h towards a railway crossing where a car waits behind the barrier. If the speed of sound is 345 m/s, what is the frequency of the sound that reaches the car as the train approaches the crossing?22.?????A train approaching a crossing sounds its horn with a frequency of 750 Hz. An observer standing at a distance down the tracks measures the frequency of the whistle to be 675 Hz as the train moves away from her. If the air temperature is 25?C, find the speed of the train in kilometres per hour.23.?????The speed of sound at an altitude of 10 km (the height at which most jumbo jets fly) is approximately 295 m/s. If a jumbo aircraft flies at speeds of 675 km/h when cruising, what is its Mach number?24.?????A space shuttle orbits Earth at approximately 26 500 km/h. If its Mach number at this speed is 25, what is the speed of sound at this altitude in metres per second?25. Draw 3 wavelengths with a wavelength of 2 cm and an amplitude of 1cm.26. If a radio wave vibrates back and forth with the frequency of 70 Hz, how many cycles will it complete in 15s?27. A piano key with a frequency of 275 Hz is hit at the same time as a 280 Hz tuning fork. How many beats will be heard in 10s?28. A vibrating tuning fork of frequency 260 Hz is held over a closed air column. If the air temperature is 20C, what length will the column be for the second and fourth resonance?29. An open air column has a length of 54cm and produces a note at the first resonance using a tuning fork of frequency 350Hz. What is the temperature in the room? Answer Section11. T = 0.60s, f = 1.7Hz 12. λ = 2.75 ? 10–2 m 13. 0.20s 14. a) 10m b) 25m/s 15. v = 3.4 ? 102 m/s 16. d = 5.2 ? 102 m 17. v = 3.5 ? 102 m/s 18. d = 5.2 ? 102 m 19. λ = 8.8m 20. f = 508 Hz or 516 Hz 21. f = 5.9 ? 102 Hz 22. v = 1.4 ? 102 km/h 23. Mach = 0.636 24. v = 2.9 ? 102 m/s 26. 1050 cycles 27. 50 beats 28. 0.99m, 2.3m 29. 78C ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download