In noisy factory environments, it’s possible to use a loudspeaker to cancel persistent low-frequency machine noise at the position of one worker. The details of practical systems are complex, but we can present a simple example that gives you the idea. Suppose a machine 5.0 m away from a worker emits apersistent 80 Hz hum. To cancel the sound at the worker’s location with a speaker that exactly duplicates the machine’s hum, how far from the worker should the speaker be placed? Assume a sound speed of 340 m/s.

The area of a typical eardrum is approximately 5.0 x 10°m². Calculate the sound power on the eardrum at: (Intensity = Power/Area) a. The threshold of hearing. b. The threshold of pain.

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Hi there. Can someone walk me through this problem? Thank you. The African cicada is the world's loudest insect, producing a sound intensity level of 107 dB at a distance of 0.50 m. What is the intensity of its sound (in W/m2) as heard by someone standing 2.3 m away?

Two loud speakers are 3m apart. A person is listening to a single pitch at 680Hz. Theperson is along the back wall, which is reasonably far, what are two directions from the center ofthe speakers where the person would expect to have the music loud? Repeat for two directionsthat are quiet.The person is now standing at the location that is 4m directly in front of one of thespeakers. Determine whether that position is loud, quiet or somewhere between the twoextremes. Explain. Use a diagram to help. [Note: Do not assume the person is far away.Comment on why that makes a difference.]

Hello, Can I please have help regarding this problem ? Thanks.    Suppose that the clock on our lecture room has a minute-hand length of 10 cm.(Use a coordinate system with the origin at center of clock and +x axis along the3PM direction and the +y direction along the 12PM direction). From the 12 to 8mark, for the tip of the minute hand:a) Sketch a vector diagram labeling ri, rf, Δr, Vi, Vf, and ΔV.b) Calculate the displacement vector in unit-vector notation.c) Calculate the average velocity vector in unit-vector notation.d) Calculate the average acceleration vector in unit-vector notation.e) Calculate magnitude and direction of the average acceleration vector.f) Calculate the magnitude and direction of the total acceleration of the tip ofthe minute hand at the 6 mark.

Suppose the purr of a cat has a sound intensity that is 370 times greater than the threshold level. Find the decible value for this cat’s purr. Round to the nearest decible. ? dB

A harvest mouse can detect sounds as quiet as -10 dBdB. Suppose you are sitting in a field on a very quiet day while a harvest mouse sits nearby. A very gentle breeze causes a leaf 1.1 mm from your head to rustle, generating a faint sound right at the limit of your ability to hear it. The sound of the rustling leaf is also right at the threshold of hearing of the harvest mouse.  How far is the harvest mouse from the leaf?