Respuestas :
A) 100km/h
B) 49km/h
C) 2.8 km/h
D) 500 m/s
Total pressure is constant and PT = P = 1/2*ρ*v^2
So p1 + 1/2*ρ*v1^2 = p2 + 1/2*ρ*v2^2 and from continuity we have ρ*A1*v1 = ρ*A2*v2
So v2 = v1*A1/A2 since r2 = 2r1 then A2 = 4A1
so v2 = v1/4
Now from above p2 = p1 + 1/2*ρ*v1^2 - 1/2*ρ*v2^2 = p1 + 1/2*ρ*v1^2 - 1/2*ρ*v1^2/4^2
So p2 = 3.0x10^4Pa + 1/2*1000kg/m^3*(12m/s)^2 - 1/2*1000kg/m^3*12^2/16
= 9.75x10^4Pa = 9.8x10^4Pa
The equation of the ellipse in <em>standard</em> form is (x + 3)² / 100 + (y - 2)² / 64 = 1. (Correct choice: B)
<h3>What is the equation of the ellipse associated with the coordinates of the foci?</h3>
By <em>analytical</em> geometry we know that foci are along the <em>major</em> axis of ellipses and beside the statement we find that such axis is parallel to the x-axis of Cartesian plane. Then, the <em>standard</em> form of the equation of the ellipse is of the following form:
(x - h)² / a² + (y - k)² / b² = 1, where a > b (1)
Where:
- a - Length of the major semiaxis.
- b - Length of the minor semiaxis.
Now, we proceed to find the vertex and the lengths of the semiaxes:
a = 10 units.
b = 8 units.
Vertex
V(x, y) = 0.5 · F₁(x, y) + 0.5 · F₂(x, y)
V(x, y) = 0.5 · (3, 2) + 0.5 · (- 9, 2)
V(x, y) = (1.5, 1) + (- 4.5, 1)
V(x, y) = (- 3, 2)
The equation of the ellipse in <em>standard</em> form is (x + 3)² / 100 + (y - 2)² / 64 = 1. (Correct choice: B)
To learn more on ellipses: brainly.com/question/14281133
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Answer:
320 degrees.
Step-by-step explanation:
B because the amount of money they earn per hour multiplied by how many hours they worked is equal to what they earned in total
