Confused About Critical Angle and Echoes?

AI Thread Summary
The discussion centers on confusion regarding critical angles and echoes in the context of beam refraction. A user calculated the first critical angle and found the incident angle to be greater, leading to no echoes due to lack of refraction. Another participant requested detailed calculations and a diagram to better understand the setup. Clarification on the calculations and visual aids is needed to resolve the confusion. The conversation emphasizes the importance of clear communication and detailed information in solving physics problems.
Nubira20
Messages
1
Reaction score
0
Homework Statement
One longitudinal US pulse was emitted inside a steel sheet that is 1cm wide at an angle of 15 o . Lubrication oil covers the backside of the steel sheet. You know that US velocity in steel is 6.2km/s and 4.1km/s for longitudinal and sheer waves, and 1.3km/s in oil. what is the (lateral) distance (on the sheet surface) between the source pulse and the longitudinal echo?
Relevant Equations
Snell's law
I calculated the first critical angle and found the incident angle here to be greater than it thus there no echoes because the beam didn't refract , but i asked a friend and he told me no and that he calculated a number .. any help ?
 
Physics news on Phys.org
Welcome to the PF. :smile:

Can you show your detailed calculations please? That will make it easier for us to help you. Thanks.
 
Not sure I understand the set-up. Please post a diagram.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Total Internal Reflection and Transmitted Wavelength
Replies
1
Views
792
Calculate a radius of a circle on a screen
Replies
3
Views
1K
What is the relationship between critical angle and negative refractive index?
Replies
6
Views
2K
What is the best shape for a soccer goal post?
4
Replies
157
Views
11K
Maximum critical angle for total reflection?
Replies
5
Views
3K
Critical angle (symmetry of refraction) confusion
Replies
5
Views
2K
Determine the relationship between θB and θA
Replies
20
Views
2K
B Shouldn't the refracted ray be along the boundary here?
Replies
5
Views
2K
Refraction through an optical fiber
Replies
3
Views
3K
Solving Refraction: Critical Angle & Min. Angle of Incidence
Replies
6
Views
1K

Hot Threads

Recent Insights

Back
Top