Explanation:
Dark Energy is a property of the entire universe. And the universe is roughly made up of 68% of this dark energy whereas dark matter makes up 27% of the universe matter.
The influence of the dark matter shows in the individual galaxies whereas dark energy acts only on the entire universe. dark matter is responsible for the gravity effect on the plants and the heavenly bodies which produces gravity force. But the dark energy is known as the anti gravity force as it is responsible for the expansion of the universe. Dark matter attracts and produces an attractive force while dark energy repels and produces a repulsive force.
Scientist believe that they exists to account for the very fact that gravity holds all the heavenly bodies and the galaxies together. They are even responsible for the fluctuation in Cosmic Microwave background. Researchers and scientist firmly believe that all the visible matter that exists may not have enough gravitational pull to hold everything together in the galaxies. And also the expanding universe strongly proves that dark energy exists in the universe.
Answer:
The focal length of the given spherical mirror is 20cm.
Explanation:
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Answer:
A) 0.660 g/ml
B) 1.297 ml
C) 0.272 g
Explanation:
Every substance, body or material has mass and volume, however the mass of different substances occupy different volumes. This is where density 
appears as a physical characteristic property of matter that establishes a relationship between the mass 
of a body or substance and the volume 
it occupies:
(1)
Knowing this, let's begin with the answers:
<h2 /><h2>Answer A:</h2>
Here the mass is 
and th volume 
Solving (1) with these values:
(2)
(3)
<h2>Answer B:</h2>
In this case the mass of a sample is 
and its density is 
.
Isolating from (1):
(4)
(5)
(5)
<h2>Answer C:</h2>
In this case the volume of a sample is 
and its density is 
.
Isolating from (1):
(6)
(7)
(8)
The North Magnetic Pole is the point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downwards (in other words, if a magnetic compass needle is allowed to rotate about a horizontal axis, it will point straight down). There is only one location where this occurs, near (but distinct from) the Geographic North Pole and the Geomagnetic North Pole.
Answer: No
Explanation:
The force F required is equal to the Force exerted in stretching the first material since conditions are the same
