1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
astraxan [27]
3 years ago
9

The word topsoil is commonly used, but not always correctly. the proper definition is ________.

Biology
1 answer:
Kaylis [27]3 years ago
8 0
The topsoil is the upper and outermost layer of soil, usually the top 2 inches to 8 inches. It contains the highest concentration of organic matter and microorganisms. Topsoil is used as the medium for all plant growth, whether it is a lawn, garden or prairie.
You might be interested in
The population of the Earth is roughly eight billion people. If all free electrons contained in this extension cord are evenly s
Agata [3.3K]

Answer:

Explanation:

the same question  was in my book hehehe so i am telling this from my book

Drift velocity: 3.32\cdot 10^{-4}m/s

2) 5.6\cdot 10^{13} electrons per person

For a current flowing through a conductor, the drift velocity of the electrons is given by the equation:

v_d=\frac{I}{neA}

where

I is the current

n is the concentration of free electrons

e=1.6\cdot 10^{-19}C is the electron charge

A is the cross-sectional area of the wire

The cross-sectional area can be written as

A=\pi r^2

where r is the radius of the wire. So the equation becomes

In this problem, we have:

I = 8.0 A is the current

is the concentration of free electrons

d = 1.5 mm is the diameter, so the radius is

r = 1.5/2 = 0.75 mm =0.75.10^-3m

Therefore, the drift velocity is:

vd=8.0/(8.5.10^28)(1.6.10^19)π(0.75.10^-3)^2=3.32.10^-4m/s

2)The total length of the cord in this problem is

L = 3.00 m

While the cross-sectional area is

A=π ^2=π (0.75.10^-3)^2=1.77.10^-6m^2

Therefore, the volume of the cord is

V=AL(1)

The number of electrons per unit volume is n, so the total number of electrons in this cord is

N=nV=nAL=(8.5.10^28)(1.77.10^-6)(3.0)=4.5.10^23

In total, the Earth population consists of 8 billion people, which is

N^1=8.10^9

Therefore, the number of electrons that each person would get is:

N^e=N/N^1=4.5.10^23/8.10^9=5.6.10^13

hope it helps

6 0
3 years ago
What is fundamental to protein structure and function?
lisov135 [29]
The two answers I have to share is:
-amino acids
-it’s shape
3 0
3 years ago
Read 2 more answers
Basic unit of structure and function in the nervous system is called
Vsevolod [243]

Answer:

a cell

Explanation:

its the most basic unit of life itself and the nervous system is made up of neurons and glial cells

6 0
3 years ago
How did Mary Montagu discover a vaccine for smallpox
insens350 [35]

Answer:

Lady Mary Wortley Montagu adapted "variolation" instead of "vaccination" to prevent smallpox in her children. She learned about it when she was in Constantinople (Turkey) with her husband. There, prisoners were intentionally inoculated with smallpox virus under their skin. When she saw that they didn't develop the disease and were among survivors, she inoculated smallpox virus to her children (son and daughter) as well using a needle. Later on, efforts of Edward Jenner towards vaccination were also recognized and it became a fashion to inoculate smallpox as a preventive measure.

5 0
3 years ago
6. What are at least 2 requirements of a good hypothesis?
steposvetlana [31]

Answer:

A scientific hypothesis must be testable, and;

A scientific hypothesis must be falsifiable.

Explanation:

I looked it up o-o sorry if its wrong. :3

3 0
2 years ago
Other questions:
  • Which intercellular communication type changes membrane permeability?
    7·2 answers
  • Tyrosine and tryptophan are less hydrophobic than phenylalanine because ________. Tyrosine and tryptophan are less hydrophobic t
    11·1 answer
  • Pls help!!
    9·2 answers
  • A gene for microtubule proteins is being made in a cell. How can mRNA represent an exact copy of that gene?
    11·2 answers
  • Determine whether heating or cooling takes place during each process:
    13·1 answer
  • The entropy of a system measures the state of disorder of the system.
    11·2 answers
  • Osmotic pressure is created by the presence in a fluid of small diffusible molecules that easily move through the capillary memb
    9·1 answer
  • How does gene flow directly contribute to evolution?
    6·1 answer
  • When does the exponential growth of a population stop?
    13·1 answer
  • What are the precautions of asthma
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!