Light that enters the new medium <em>perpendicular to the surface</em> keeps sailing straight through the new medium unrefracted (in the same direction).
Perpendicular to the surface is the "normal" to the surface. So the angle of incidence (angle between the laser and the normal) is zero, and the law of refraction (just like the law of reflection) predicts an angle of zero between the normal and the refracted (or the reflected) beam.
Moral of the story: If you want your laser to keep going in the same direction after it enters the water, or to bounce back in the same direction it came from when it hits the mirror, then shoot it <em>straight on</em> to the surface, perpendicular to it.
Answer:
creo que es la a ..........
Answer:
2.6h
Explanation:
I attached the image below of the work hope you can see it. Hope this helps!
Explanation:
It is given that,
Frequency of diagnostic ultrasound, f = 3.82 MHz = 3820 Hz
The speed of the sound in air, v = 343 m/s
(a) We need to find the wavelength in air of such a sound wave. Let it is given by λ₁
i.e. 
(b) If the speed of sound in tissue is 1650 m/s .
Hence, this is the required solution.
Answer:
IT IS HOSPITAL OR AMBULANCE
SOME THING LIKE THAT IS WRITTEN ZOOM THAT PHOTO MORE
