Answer:
A. Both exceed the matter-energy equivalent of luminous matter.
B. Dark matter has only an attractive gravitational effect, while dark energy is repulsive.
Explanation:
Dark matter and dark energy together constitute about ninety-five percent of the of total matter-energy equivalence in the universe. So, they exceed the matter-energy equivalent of luminous matter.
Dark energy is the repulsive force that is accelerating the expansion of the universe. Dark matter only has an attractive gravitational effect but does not interact with light of any kind.
Answer:
B
Explanation:
The Himalayan Mountains formed at a convergence plate boundary between the Eurasian plate and the Indian plate.
N = 1 - (QC/QH)
n = efficiency
QC = Cold Reservoir = 220 K
QH = Hot Reservoir = 680 K
![n = 1 - (220 \div 680) (\div 10)\\ n = 1 - (22 \div 68) (\div 2) \\ n = 1 - (11 \div 34) \\ n = (34 - 11) \div 34 \\ n = 23 \div 34 \\ n = 0.676... \times 100\\ n = 67.6](https://tex.z-dn.net/?f=n%20%3D%201%20-%20%28220%20%5Cdiv%20680%29%20%28%5Cdiv%2010%29%5C%5C%20n%20%3D%201%20-%20%2822%20%5Cdiv%2068%29%20%28%5Cdiv%202%29%20%5C%5C%20n%20%3D%201%20-%20%2811%20%5Cdiv%2034%29%20%5C%5C%20n%20%3D%20%2834%20-%2011%29%20%5Cdiv%2034%20%5C%5C%20n%20%3D%2023%20%5Cdiv%2034%20%5C%5C%20n%20%3D%200.676...%20%5Ctimes%20100%5C%5C%20n%20%3D%2067.6)
Answer: The engine's efficiency is 67.6% .
Answer:
The acceleration is about 9.8 m/s2 (down) when the ball is falling.
Explanation:
The ball at maximum height has velocity zero
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.8 m/s² (positive downward and negative upward)
![v=u+at\\\Rightarrow 0=u-9.8\times t\\\Rightarrow u=9.8t](https://tex.z-dn.net/?f=v%3Du%2Bat%5C%5C%5CRightarrow%200%3Du-9.8%5Ctimes%20t%5C%5C%5CRightarrow%20u%3D9.8t)
The accleration 9.8 m/s² will always be acting on the body in opposite direction when the body is going up and in the same direction when the body is going down. The acceleration on the body will never be zero
With the use of below formula, at 879 °C, velocity will be double the velocity at 15 °C.
<h3>
What is the relationship between Velocity and sound ?</h3>
The velocity of sound waves in air is proportional to the square root of Thermodynamic temperature. That is, V = K![\sqrt{T}](https://tex.z-dn.net/?f=%5Csqrt%7BT%7D)
Given that the temperature at which the velocity of sound in air is twice its velocity at 15°C, Let us make use of the formula;
(v2/v1) = √(T2 / T1)
Where
- T2 = final absolute temperature
- T1 = initial temperature.
Recall that absolute temperature = °C + 273.
If v2 = 2 × v1 and temperature in degree Celsius = 15°C, then,
Temperature in Kelvin K = 15 + 273 = 288
Substitute all the parameters into the formula
(2 × v1)/v1 = √(T2/288)
2 = √ (T2 /288)
Square both sides
4 = (T2/288)
T2 = 4 × 288
T2 = 1152K
Temperature in degrees Celsius = 1152 - 273 = 879 °C.
Therefore, at 879 °C, velocity will be double the velocity at 15 °C.
Learn more about sound waves here: brainly.com/question/13105733
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