Answer:
t = 2.2 s
Explanation:
Given that,
A person observes a firework display for A safe distance of 0.750 km.
d = 750 m
The speed of sound in air, v = 340 m/s
We need to find the between the person see and hear a firework explosion. let it is t. So, using the formula of speed.

So, the required time is 2.2 seconds.
Sonar<span> (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.</span>
Answer:
Total internal reflection is going on. The refractive index of water is about 1.3, so sin 90/sin r=1/sinr=1.3. So the fish can only see objects outside the water within about 50 degrees of the vertical
Answer:
Maybe put them in order ????
Explanation:
Answer:
n=2.053
Explanation:
We will use Snell's Law defined as:

Where n values are indexes of refraction and
values are the angles in each medium. For vacuum, the index of refraction in n=1. With this we have enough information to state:

Solving for
yields:

Remember to use degrees for trigonometric functions instead of radians!