Sea scorpions or Eurypterids lived about 251.9 million years ago. They were formidable predators and hunters, but they were wiped out in the Great Permian Mass Extinction, which is also known as the Great Dying (96% of all species on Earth went extinct).The largest species like Jaekelopterus was over 7 feet long! They were mainly thought to go extinct because of a slew of natural disasters that occurred when a comet hit the Earth, as well as increased volcanic activity polluting the seas that Sea scorpions lived in, as well as rising sea temperatures. The Silurian, when these Sea scorpions proliferated was when the water was cooler, holding in more nutrients, allowing both Sea Scorpions and other animals to spread all over the world. But as the oceans became polluted from the volcanoes (and the ash they produced) and the global ocean temperatures began to rise, many animals may not have been able to cope or adapt to the extreme change, becoming helpless in their nutrient deficient water (compared to what they were used to).
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Answer:
The surface tension is 0.0318 N/m and is sufficiently less than the surface tension of the water.
Solution:
As per the question:
Radius of an alveolus, R = 
Gauge Pressure inside, 
Blood Pressure outside, 
Now,
Change in pressure, 
Since the alveolus is considered to be a spherical shell
The surface tension can be calculated as:


And we know that the surface tension of water is 72.8 mN/m
Thus the surface tension of the alveolus is much lesser as compared to the surface tension of water.
C. Insulator
It COULD be semi-insulator but i'm sure its C
Newton’s first law is commonly stated as:
An object at rest stays at rest and an object in motion stays in motion.
However, this is missing an important element related to forces. We could expand it by stating:
An object at rest stays at rest and an object in motion stays in motion at a constant speed and direction unless acted upon by an unbalanced force.
By the time Newton came along, the prevailing theory of motion—formulated by Aristotle—was nearly two thousand years old. It stated that if an object is moving, some sort of force is required to keep it moving. Unless that moving thing is being pushed or pulled, it will simply slow down or stop. Right?
This, of course, is not true. In the absence of any forces, no force is required to keep an object moving. An object (such as a ball) tossed in the earth’s atmosphere slows down because of air resistance (a force). An object’s velocity will only remain constant in the absence of any forces or if the forces that act on it cancel each other out, i.e. the net force adds up to zero. This is often referred to as equilibrium. The falling ball will reach a terminal velocity (that stays constant) once the force of air resistance equals the force of gravity.
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