Answer:
The actual elevation angle is 12.87 degrees
Explanation:
In the attachment you can clearly see the situation. The angle of elevation as seen for the scuba diver is shown in magenta, we conclude that
.
Using Snell's Law we can write:

,
Let's approximate the index of refraction of the air (medium 1 in the picture) to 1.
We thus have:

. Calling
the actual angle of elevation, we get from the picture that
Answer:
Explanation:
Speed is scalar and velocity is vector. Vector values imply direction as well as magnitude. Therefore, speed and velocity are not the same. The speeds of these 2 planes are the same at 300km/hr, but the velocity of the plane traveling north is +300km/hr while the velocity of the plane traveling south is -300km/hr if we define north as positive and south as negative.
E = mass x gravity x height
You do 1000 divide it by 10 which equals 100 W