Answer: The given statement is true.
Transport of oxygen from the air takes place through respiratory system. Oxygen from air ( that is taken from the atmosphere) enters via a system of tubes, into our lungs and then it is released into the bloodstream ( to serve in various organs) whereas opposite route is followed by CO2 ( carbon dioxide).
In the respiratory tract, the nose is lined by mucosal epithelium that possessed glands ( which secrete thick mucus). Due to this, air is moistened. Beneath the epithelium surface, there lies network of blood vessels that help in warming the nasal cavity and thus the air is warmed.
Answer: True
Explanation: On Edge 2020
The statement about "A wedge is simply a form of an inclined plane" is false. The pivot joint is the lever and the wedge are the blades of the scissors. This is to efficiently exert force on an object to cut it.
When two electron in a chemical bond are equally shared between two different atoms, the bond is covalent bond.
A chemical bond known as a covalent bond includes the exchanging of electrons between atoms to create electron pairs.
These electron couples are referred to as bonding pairs or sharing pairs. Covalent bonding is the stable equilibrium of attracting and repulsive forces that exists when two atoms share an electron.
The ability of each atom to reach the equivalent of a full valence shell, which corresponds to a stable electronic state, is made possible for many molecules by the sharing of electrons. Hence, when two electron in a chemical bond are equally shared between two different atoms, the bond is covalent bond.
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The final object will move with a speed of 1.9 x 10⁻² m/s.
According to the law of conservation of momentum, when two objects meet in a closed system, the sum of their momentums before and after the collision is constant.
Here,
Initial velocity of the bullet, u = 100 m/s
Mass of the bullet, m = 15 g = 0.015 kg
Mass of the object, M = 75 kg
Total momentum before collision, P₁ = mu + (M x 0)
P₁ = 0.015 x 100
P₁ = 1.5 Kgm/s
Total momentum after collision, P₂ = (m + M)v
P₂ = (0.015 + 75)v
P₂ = 75.015 v
According to law of conservation of momentum,
P₁ = P₂
1.5 = 75.015 v
Therefore, the speed with which the final object moves,
v = 1.5/75.015
v = 1.9 x 10⁻² m/s
Hence,
The final object will move with a speed of 1.9 x 10⁻² m/s.
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Alicia ran 15 miles at the faster pace.
Let Alicia run with the speed of 12mph for A hours and with the speed of 8mph for B hours.
Total distance is 21 miles, so we can make the first equation as:
12A + 8B = 21 .............(i)
Now the total time taken is 2 hours, which means:
A + B = 2 ..............(ii)
Now multiply equation (ii) by 8 and subtract from equation (i)
then we get, 4A = 5
A = 5/4 hours
So Alicia run at the speed of 12mph for 5/4 hours, total distance covered is:
d = 12 × 5/4
d = 15 miles
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Answer:
15 miles
Explanation:
Alicia's speed in the first part of the race is:
where is the length of the first part and the time taken to cover this part.
Alicia's speed in the second part of the race is:
where is the length of the second part and the time taken to cover this part.
The total length of the race is
And the total time taken by Alicia to complete the race is
We have in total 4 equations with 4 unknown quantities. From the first 2 equations we find:
And substituting into the second group of equations:
Calling A the first equation and B the second equation, if we compute (A-8B) we get:
And so
So Alicia runs for 1.25 hours at 12 mph (second part of the race). Therefore, the distance travelled during this part is:
Therefore the answer is 15 miles.
The electromagnet can be adjusted for having different levels of magnetic fields by turning it on and off. Hence, option (D) is correct.
Electromagnets are made by winding a wire through a magnetic material such as a soft iron core making a coil and then passing an electric current through the coil thus making the soft iron core magnetic.
The characteristics of electromagnets are as follows -
Thus, we can conclude that the electromagnet can be adjusted for having different levels of magnetic fields by turning it on and off. Hence, option (D) is correct.
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D Electromagnets can easily be turned on and off.