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3 years ago

The most important barriers to diffusion today are physical features of Earth's surface.

Physics

1 answer:

nikdorinn [45]3 years ago

7 0

Answer:

False

Explanation:

Physical features of earth's surface like mountains, deserts and oceans are not the barriers in today's modern world. Technological improvements in the transportation and communication has removed these barriers. So they are not barriers anymore.

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Calculate the energy of a photon of electromagnetic radiation whose frequency is 2.94 x 10 to the 14th xbox one

DIA [1.3K]

Answer:

$1.95\cdot 10^{-19} J$

Explanation:

The energy of a photon is given by:

$E=hf$

where

$h=6.63\cdot 10^{-34}Js$ is the Planck constant

$f=2.94\cdot 10^{14} Hz$ is the frequency of the photon

Substituting the numbers into the equation, we find:

$E=(6.63\cdot 10^{-34} Js)(2.94\cdot 10^{14} Hz)=1.95\cdot 10^{-19} J$

3 0

2 years ago

What is the equivalent volume occupied by three milliliters of water?

goldenfox [79]

Three cubic centimeters

7 0

3 years ago

Read 2 more answers

Which of the following has the least amount of kinetic energy?

alexandr1967 [171]

Answer:

a 10 kg elephant moving at 1 m/s

Explanation:

because kinetic energy depend on how fast an object moves and also depend on the gravitational force which include the weight.

8 0

3 years ago

Three positive charges A, B, and C, and a negative charge D are placed in a line as shown in the diagram. All four charges are o

polet [3.4K]

Answer:

a. charge C experiences the greatest net force, and charge B receives the smallest net force

b. ratio=9

Explanation:

<u>Electrostatic Force</u>

Two point-charges $q_1$ and $q_2$ separated a distance d will exert a force on each other of a magnitude given by the Coulomb's formula

$\displaystyle F=\frac{k\ q_1\ q_2}{r^2}$

Where k is the proportional constant of value

$k=9*10^9\ N.m^2/c^2$

The diagram provided in the question shows four identical charges (let's assume their value is Q) separated by identical distance (of value d). The force between the charges next to others is

$\displaystyle F_1=\frac{k\ Q\ Q}{d^2}$

$\displaystyle F_1=\frac{k\ Q^2}{d^2}$

The force between charges separated 2d is

$\displaystyle F_2=\frac{k\ Q^2}{(2d)^2}$

$\displaystyle F_2=\frac{k\ Q^2}{4d^2}$

And the force between the charges A and D is

$\displaystyle F_3=\frac{k\ Q^2}{(3d)^2}$

$\displaystyle F_3=\frac{k\ Q^2}{9d^2}$

Now, let's analyze each charge and the force applied to them by the others

Let's recall equally signed charges repel each other and differently signed charges attrach each other

Charge A. It receives force to the left from B and C and to the right from D

$\displaystyle F_A=-F_1-F_2+F_3=-\frac{k\ Q^2}{d^2}-\frac{k\ Q^2}{4d^2}+\frac{k\ Q^2}{9d^2}$

$\displaystyle F_A=\frac{k\ Q^2}{d^2}(-1-\frac{1}{4}+\frac{1}{9})$

$\displaystyle F_A=-\frac{41}{36}F_1$

Charge B. It receives force to the right from A and D and to the left from C

$\displaystyle F_B=F_1-F_1+F_2=\frac{k\ Q^2}{d^2}-\frac{k\ Q^2}{d^2}+\frac{k\ Q^2}{4d^2}$

$\displaystyle F_B=\frac{1}{4}F_1$

Charge C. It receives forces to the right from all charges.

$\displaystyle F_C=F_2+F_1+F_1=\frac{k\ Q^2}{4d^2}+\frac{k\ Q^2}{d^2}+\frac{k\ Q^2}{d^2}$

$\displaystyle F_C=\frac{9}{4}F_1$

Charge D. It receives forces to the left from all charges

$\displaystyle F_D=-F_3-F_2-F_1=-\frac{k\ Q^2}{9d^2}-\frac{k\ Q^2}{4d^2}-\frac{k\ Q^2}{d^2}$

$\displaystyle F_D=-\frac{49}{36}F_1$

Comparing the magnitudes of each force is just a matter of computing the fractions

$\displaystyle \frac{41}{36}=1.13,\ \frac{1}{4}=0.25,\ \frac{9}{4}=2.25,\ \frac{49}{36}=1.36$

We can see the charge C experiences the greatest net force, and charge B receives the smallest net force

The ratio of the greatest to the smallest net force is

$\displaystyle \frac{\frac{9}{4}}{\frac{1}{4}}=9$

The greatest force is 9 times the smallest net force

7 0

3 years ago

How did the South American plate and African plate move?

garri49 [273]

Answer:

How did the South American Plate and African Plate move? Earth's plates move on top of a soft, solid layer of rock called the mantle. ... The South American and African Plates moved apart as a divergent boundary formed between them and an ocean basin formed and spread.

Explanation:

pls make me brainliest

4 0

2 years ago

Read 2 more answers