Recent content by j.c

nevermind we got it! sorry

Homework Statement the laws of refraction and reflection are the same for sound as for light. the speed of sound is 340 m/s in air and 1510 m/s in water. if a sound wave traveling in air approaches a plane water surface at an angle of incidence 12°, what is the angle of refraction? Homework...

oh ok. thank you! I came to the conclusion of nine after your first post but that seemed almost too simple and i didnt want to embarass myself with a wrong answer haha. :)

so then... an increase of 10 dB means that the intensity of the sound is multiplied by a factor of ten right? but I'm still confused about how to get the number of machines that can be added

Homework Statement a noisy machine in a factory produces a decibel rating of 80 dB. how manyidentical machines could you add to the factory without exceeding the 90-dB limit? Homework Equations I=P/A and B+10log(I/I(sub)0) ... (I think) The Attempt at a Solution I tried to find...