Answer:
v₂ = 70 m / s
Explanation:
For this exercise let's use Bernoulli's equation
where subscript 1 is for the top of the mountain and subscript 2 is for Tuesday's level
P₁ + ½ ρ v₁² + ρ g y₁ = P₂ +1/2 ρ v₂² + ρ g y₂
indicate that the pressure in the two points is the same, y₁ = 250 m, y₂ = 0 m, the water in the upper part, because it is a reservoir, is very large for which the velocity is very small, we will approximate it to 0 (v₁ = 0), we substitute
ρ g y₁ = ½ ρ v₂²
v₂ =
let's calculate
v₂ = √( 2 9.8 250)
v₂ = 70 m / s
Answer:
A: The acceleration is 7.7 m/s up the inclined plane.
B: It will take the block 0.36 seconds to move 0.5 meters up along the inclined plane
Explanation:
Let us work with variables and set

As shown in the attached free body diagram, we choose our coordinates such that the x-axis is parallel to the inclined plane and the y-axis is perpendicular. We do this because it greatly simplifies our calculations.
Part A:
From the free body diagram we see that the total force along the x-axis is:

Now the force of friction is
where
is the normal force and from the diagram it is 
Thus
Therefore,

Substituting the value for
we get:

Now acceleration is simply

The negative sign indicates that the acceleration is directed up the incline.
Part B:

Which can be rearranged to solve for t:

Substitute the value of
and
and we get:
which is our answer.
Notice that in using the formula to calculate time we used the positive value of
, because for this formula absolute value is needed.
Answer:
There are no gaps in space between the photons as they travel. If you were to look at a wave then you'd come to a conclusion that indeed that there aren't any gaps unless they are specifically placed.The light from a distance star indeed spreads out and weakens as it travels, but this just reduces the wave strength and does not introduce gaps.