Answer:
Yucatán Peninsula in Mexico
Explanation:
It is called the Chicxulub Asteroid.
P waves is moved by compressing and expanding.
S waves is form perpendicular angle when they pass.
Answer:
True
Explanation:
The semi-major axis of an ellipse is half the length of its major axis.
Answer:
b. flat rotation curves in spiral galaxies
Explanation:
Dark matter accounts for majority of the matter in the universe (about 85%). It is considered to be composed of subatomic particles which are yet to be discovered. Dark matter cannot be observed because it does not emit light that can be detected. Only its gravitational effect is visible.
Astronomers when calculated the mass of the visible matter and tried to account for the observed speed of stars in the galaxy, there was a mismatch. To understand what caused this mismatch, astronomers gave name to the invisible matter as the Dark Matter.
The expected velocity of stars should decrease away from the near the center of the galaxy but a constant velocity of stars was observed that is a relatively flat rotation curve was obtained.
Thus, flat rotation curves in spiral galaxies in an evidence of Dark Matter.
Answer:
x = 7, y = 2
Explanation:
Two triangles are said to be congruent if all three sides and three angles of one triangle is equal to three sides and three angles of the other triangle.
From the question:
BD ≅ BD (reflexive property of equality)
Since BD is the angle bisector of ∠ABC, hence ∠ABD = ∠CBD
∠ABD = 2x + y, ∠CBD = 14 + y. Therefore:
2x + y = 14 + y
2x = 14 + y - y
2x = 14
x = 14 / 2
x = 7
Also, ∠BAD = ∠BCD = 90° (right angled triangle)
Since ∠BAD = ∠BCD, BD ≅ BD and ∠ABD = ∠CBD, therefore ΔABD is congruent to ΔCBD by angle-angle-side congruence theorem.
The angle-angle-side congruence theorem states that if two angles and one side of one triangle is equal to two angles and one side of another triangle the both triangles are congruent.
ΔABD is congruent to ΔCBD, therefore AD = CD
5x - y = x + 13y
13y + y = 5x - x
14y = 4x
14y = 4(7)
y = 4(7) / 14
y = 2
