Coherent= both speakers in same phase, same f/wavelength. i.e they go up and down at the same time
Fringes= gap between max and minimum sound.
Where you see the circle on the RHS diagram, the waves will be in phase. So will always get a MAXIMUM amplitude. This is as the waves meeting are both at peaks or troughs.
· Diffraction makes waves spread out
· Waves pass through each other
· Principle of superposition
· Interference pattern
· In phase
· Out of phase
· Maximum
· Minimum
Figure A
Fringes= gap between max and minimum sound.
In phase- both waves meet with the same f.
Out of phase= each wave meets with a different f.
Where you see the circle on the RHS diagram, the waves will be in phase. So will always get a MAXIMUM amplitude. This is as the waves meeting are both at peaks or troughs.
Between the maximums there is a MINIMUM amplitude. This is in the MIDDLE of the two maximums, as between two peaks there is a TROUGH. The minimum is formed when a peak wave meets a trough wave.
Therefore when you walk across, you hear fringes (a line of maximums, followed by a line of minimums, max, min, max...)
As the diagram gets bigger/extends the waves will get more spread out.
Therefore when you walk across, you hear fringes (a line of maximums, followed by a line of minimums, max, min, max...)
As the diagram gets bigger/extends the waves will get more spread out.
Young's double split experiment proved that light had wave properties as it obeyed the laws of diffraction and interference.
2 source interference pattern- Key points/words:
· 2 sources – coherent= in phase, same f/wavelength· Diffraction makes waves spread out
· Waves pass through each other
· Principle of superposition
· Interference pattern
· In phase
· Out of phase
· Maximum
· Minimum
Figure A
Lasers:
- Red light will make less frequent fringes
- Blue light will make more frequent fringes
- DVDs- Blue ray can store more info
- There will be a limit to how much info it can store as you need the fringes for diffraction to happen
- This is why you cant see very small words on a poster far away. The rays from the text come into your eye very small and the rays from each letter comes cross over the rays of the adjacent letter, which causes the word to form on your re