A. From a distance, you view an engineer driving a stake in the ground at a rate of one stroke per second; the sound of the blows on the stake are synchronized with the blows you see. After the hammering, you hear one more blow. What is the frequency of the hammer blows?!
B. Certain fish in mangrove swamps catch insects by shooting a stream of water at the insect, causing it to fall into the water. Where should a submerged fish aim a stream of water to hit an insect it sees on a leaf above the water: above the insect, below the insect, or directly at it? Explain.
2006-12-09 12:26:29 · 2 answers · asked by Anonymous in Environment
The frequency is still 1 blow/second. The fact that you're standing so far away the sound waves take that long to reach you doesn't change that.
I'm not sure a submurged fish would be able to see it anyway, since most of the light reflects off the surface and the light that does penitrate the surface hits the bottom and then back up and reflects back down. It's pretty hard to see out of water.
I'm sure that's not the answer you want, though. I'd say Above because of the influence of gravity pulling the water down in an arc and also because of the refraction of light caused by the surface.
Also, I'm not sure I know what I'm talking about. <3
2006-12-09 12:38:58 · answer #1 · answered by socialdeevolution 4 · 0⤊ 0⤋
1.100mHz
2.above the insect
2006-12-09 20:34:46 · answer #2 · answered by Jordan 3 · 0⤊ 0⤋