Answer:
Explanation:
In the first moments after the Big Bang, the universe was extremely hot and dense. As the universe cooled, conditions became just right to give rise to the building blocks of matter – the quarks and electrons of which we are all made. A few millionths of a second later, quarks aggregated to produce protons and neutrons. Within minutes, these protons and neutrons combined into nuclei. As the universe continued to expand and cool, things began to happen more slowly. It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms. These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe. Present observations suggest that the first stars formed from clouds of gas around 150–200 million years after the Big Bang. Heavier atoms such as carbon, oxygen and iron, have since been continuously produced in the hearts of stars and catapulted throughout the universe in spectacular stellar explosions called supernovae.
But stars and galaxies do not tell the whole story. Astronomical and physical calculations suggest that the visible universe is only a tiny amount (4%) of what the universe is actually made of. A very large fraction of the universe, in fact 26%, is made of an unknown type of matter called "dark matter". Unlike stars and galaxies, dark matter does not emit any light or electromagnetic radiation of any kind, so that we can detect it only through its gravitational effects.
An even more mysterious form of energy called “dark energy” accounts for about 70% of the mass-energy content of the universe. Even less is known about it than dark matter. This idea stems from the observation that all galaxies seems to be receding from each other at an accelerating pace, implying that some invisible extra energy is at work.
Answer:
.C. Refraction of light passing through the lens.
Explanation:
The convergence or divergence of the rays of light is only due to refraction of light. When a ray of light is made to pass through a lens, it bend's from it's original path. This bending of light from its original path is called Refraction. Whereas in Reflection the ray of light is reflected back into the same medium.
Hence the correct option is C. Refraction of light passing through the lens.
Answer:
3.60342 seconds
Explanation:
v = Initial velocity of snowball = 25 m/s
g = Acceleration due to gravity = 9.81 m/s²
= First angle = 75°
The second angle will be
Horizontal speed for first throw
Horizontal speed for second throw
Horizontal range is given by
Time period for first throw
Time period for second throw
The time difference is
The second ball should be thrown 3.60342 seconds later
In case 1, the torque is given by the product between the force and the arm:
In case 2, the torque is given by the product between the component of the force perpendicular to the arm and the arm itself, so we have:
and since
is larger than 1, than the torque in case 2 is larger than the torque in case 1.
<span>Water will diffuse down gradients of water potential, just as heat will flow down gradients of temperature and rocks will roll down gradients of gravitational potential</span>
