A rifle is fired in a balley with parallel vertical walls. The echo fom one wall is heard 1.61 s after the rifle was fired. The echo from the other wall is heard 2.9 s after the first echo. The velocity if sound is 343 m/s. How wide is the valley? Answer in units of m.
I've tried this problem 3 different ways and i got it wrong each time.
I would assume
x1 = (343 m/s)(1.61s)
x2 = (343 m/s)(2.9 s)
x1+x2 = width of the valley. but it's not.
please help!
2006-12-10 09:38:20 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
speed = distance/ time
distance= speed x time
distance = (343 x 1.62)2
(this is because the shot on the other wall is heard 2.9s after the first one and so add an extra one)
=1111.32m
distance = 343 x 2.9
=994.7
total width=1111.32 + 994.7
=2106.02m
2006-12-10 09:45:25 · answer #1 · answered by Ryujin 3 · 0⤊ 1⤋
The answer is wrong because the sound travels from the gun to the wall and then back to the gun. Therefore x1 is twice the distance from the gun to the wall and x2 is twice the distance from the gun to the second wall. Therefore your answers for x1 and x2 are correct, but the width of the valley is (x1+x2)/2.
2006-12-10 09:48:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
x1 = 343 x 1.61 = 552.23m(there and back)
so, 276.12 one direction right
x2 = 343 x 2.9 = 118.28m(there and back)
so, 59.14 one direction left
276.12 + 59.14 = 335.26 m wide
2006-12-10 09:48:09 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Wow. You people really get into this! I hope this is for a class assignment or something, because if not, you really need to find a hobby or something. Jeeze...
2006-12-10 09:48:51 · answer #4 · answered by Cameron K 1 · 0⤊ 0⤋
ryujin is wrong. idiot. this is just NOT RIGHT.
2014-05-12 02:27:10 · answer #5 · answered by Nicholas 3 · 0⤊ 0⤋