Answer:
v = at + u

Explanation:
acceleration, a = constant
As we know that acceleration is the rate of change of velocity


integrate on both sides

v = at + u
Where, u is the integrating constant and here it is equal to the initial velocity
Now we know that the rate of change of displacement is called velocity


Integrate on both sides


where, xo is the integrating constant which is initial position of the particle.
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:
The liquid formed from a melted solid has the same mass as the solid has.
Explanation:
As long as no water can escape, the mass of the ice before melting must equal the mass of the liquid water after.