Homework Statement
A bat is pursuing an insect, and using echolocation of 41 kHz sound waves to track the insect. The insect is initially 34 cm from the bat but then moves to a distance of 44 cm as it tries to escape. What is the difference in the two echo times that the bat measures...
Homework Statement
A sound wave has an intensity level of 49 dB. What is the pressure amplitude of this wave?
Po= 2x10^-5
Homework Equations
β=10log(I/I0)
I≈P^2
The Attempt at a Solution
I can't figure out why I'm getting this problem wrong. So I set it up, 49=10log(I/I0)
->...
I feel like such an idiot. I forgot a key part of the equation when calculating... dividing the force by the area! So that would by why I kept getting the answers wrong on the homework and figured I must be forgetting missing something.
Thanks for your patience and help.
What I'm having trouble with is how to define the force from the end that would include the other rod- if I'm just looking at the aluminum section, it's got the force pushing on it from one end, 8440 N, and on the other end it has 8440N force pushing in the opposite direction, plus what ever...
Well, the force is applied to both ends, so I took a guess and multiplied the force by 2 and then used that to try to solve for compression of aluminum. Didn't work.
I tried taking the force x2, then using the youngs modulus to try to find ΔL but was getting the wrong answer. Does the compression of the steel affect the side of aluminum that is touching it? do both sides of the bar compress?
Homework Statement
Two bars, one composed of aluminum and one of steel are place end to end as shown in Figure P11.60. The bars are both initially of length L = 24 cm, and both have a square cross section with h = 3.9 cm. If a compressive force of F = 8440 N is applied to each end, find the...