Maximums on a Diffraction Grating

Click For Summary

Homework Help Overview

The problem involves a diffraction grating created by an array of parallel wires with a specified spacing, analyzing the conditions for maximum intensity of ultrasound waves incident on the array. The context includes parameters such as the frequency of the ultrasound and the speed of sound in air.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss how to derive the wavelength from the given speed of sound and frequency. There is an exploration of the relevance of the speed of sound in the context of the diffraction problem. Some participants express uncertainty about the necessity of knowing the number of lines in the array.

Discussion Status

The discussion is ongoing, with some participants seeking clarification on the relationship between frequency and wavelength. Guidance has been provided regarding the importance of calculating the wavelength, which has helped one participant progress in their understanding.

Contextual Notes

Participants are navigating assumptions about the problem setup, including the implications of the given parameters and the conditions for maxima in diffraction patterns.

MicahP
Messages
8
Reaction score
0

Homework Statement



Consider an array of parallel wires with uniform spacing of 1.40 cm between centers. In air at 20.0°C, ultrasound with a frequency of 35.6 kHz from a distant source is incident perpendicular to the array. (Take the speed of sound to be 343 m/s.)

(a) Find the number of directions on the other side of the array in which there is a maximum of intensity. (State the number of angles for which there is a maximum of intensity. An angle above the horizontal and an angle below the horizontal count as two separate angles. If there is a maximum at the horizontal, it also counts as an angle.)


(b) Find the angle for each of these directions relative to the direction of the incident beam. (State the angles corresponding to maxima of intensity for each value of m. If there does not exist a maximum of intensity for a given value of m, enter 'NONE' in the answer blank.)

Homework Equations



d sin θ = mλ

The Attempt at a Solution



I really have no idea. I know that this is a diffraction problem, but that's about it. I feel like giving the speed of sound is the hint in the question, but I don't see the relevance...
 
Physics news on Phys.org
How do you get the wavelength λ from the speed of the wave and from its frequency?


ehild
 
You are on the right track. It is useful to know the wavelength of the waves... Can you get that from what you have been given?
 
I got it, that helped me along. What was throwing me off was that for some reason I thought I needed to know how many lines there were. Thanks!
 

Similar threads

Problem on Diffraction Grating and Laser Crystallography
  • · Replies 10 ·
Replies
10
Views
3K
Maxima in a diffraction grating
  • · Replies 2 ·
Replies
2
Views
3K
Diffraction Grating wavelength
  • · Replies 3 ·
Replies
3
Views
2K
Diffraction Grating Vs Double-Slit: Small angle Approx.
  • · Replies 1 ·
Replies
1
Views
8K
Diffraction grating problem involving Snell's Law
  • · Replies 3 ·
Replies
3
Views
6K
What Is the Longer Wavelength in a Diffraction Grating Experiment?
  • · Replies 3 ·
Replies
3
Views
3K
The Diffraction Grating (Grade 12 Physics)
  • · Replies 1 ·
Replies
1
Views
2K
Calculating the Number of Lines on a Diffraction Grating
  • · Replies 8 ·
Replies
8
Views
27K
Single-sit vs. Double-slit vs. Diffraction grating
  • · Replies 4 ·
Replies
4
Views
5K
Electron Velocity Diffraction Grating Problem
  • · Replies 4 ·
Replies
4
Views
2K