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katen-ka-za [31]
4 years ago
10

How much ancient plant debris is necessary to form one foot of coal?

Physics
1 answer:
jenyasd209 [6]4 years ago
3 0
It is said that ten feet of ancient plant debris was needed in order to make one foot of coal. This is true because fossil fuels were formed from plants and animals that lived 300 million years ago in primordial swamps and oceans. <span>Eventually, many of the seas receded and left dry land with fossil fuels like the one you are talking about, coal</span>
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A cell membrane consists of an inner and outer wall separated by a distance of approximately 10nm10nm. Assume that the walls act
Mademuasel [1]

Answer:

the correct answue are  B, A, C, C, B

Explanation:

1) The electric field is requested, let's approximate the membrane by a parallel plate with surface charge density

         E = \frac{\sigma }{2 \epsilon_o }

         E = \frac{ 10^{-5}}{2 \ 8.85 \ 10^{-12}}

         E = 5.65 10⁵ N / C

the correct answer is B

2) A calcium ion has two positive charges, so the force applied by each side of the membrane (plate)

         F = q E

         F = 2  1.6 10⁻¹⁹  5.65 10⁵

         F = 1.8 10⁻¹³ N

the total force is the sum of the force of each membrane and the two forces go to the same side

         F = total = 2 F

         F_total = 3.6 10⁻¹³ N

the correct answer is A

3) the field and the electric potential are related

          ΔV = - E s

          ΔV = - 5.65 10⁵  10 10⁻⁹

          ΔV = - 5.65 10⁻³ V

          the correct answer is C

4) In the exercise they indicate that the outer wall has a positive charge, therefore, as they indicate that we approximate the system to a capacitor, the inner wall must be negatively charged.

The electric field goes from the positive to the negative charge, which is why it goes from the outer wall to the inner wall

the correct answer is C

5) For this part we use conservation of energy

starting point. On the inside wall, brown

            Em₀ = U = qV

final point. On the outside

             Em_f = K

energy is conserved

           Em₀ = Em_f

           q V = K

            K = 3 10⁻¹⁵  5.65 10⁻³

            K = 1.7 10⁻¹⁷ J

the correct answer is B

4 0
3 years ago
Simplified. The absorption spectra of ions have been used to identify the presence of the elements in the atmospheres of the sun
Nookie1986 [14]

Answer:

The answer is "3.83 \times 10^9 \ m"

Explanation:

Z=2, so the equation is E= \frac{-4B}{n^2}

Calculate the value for E when:  

n=2 and n=9

The energy is the difference in transformation, name the energy delta E Deduct these two energies  

In this transition, the wavelength of the photon emitted is:

\Delta E=2.18 \times  10^{-18} ( \frac{1}{4}- \frac{1}{81})

\lambda = \frac{h c}{\Delta E}

h ( Planck's\  constant) = 6.62 \times  10^{(-34)} \ Js \\\\ speed \ of \ light = 3 \times 10^{8} \ \frac{m}{s}\\\\= \frac{6.62 \times 10^{(-34)} \times 3 \times 10^ {8}}{2.18 \times  10^{-18}} (\frac{1}{4}- \frac{1}{81}) \\\\=3.83 \times 10^9 \ m\\\\

6 0
3 years ago
Tarzan, who weighs 849 N, swings from a cliff at the end of a 18.0 m vine that hangs from a high tree limb and initially makes a
loris [4]

Answer:

Part a)

T = 342.5 \hat i + 675\hat j

Part b)

F_{net} = 342.5\hat i - 174\hat j

Part c)

F = 384.2 N

Part d)

\theta = 333 degree

Part e)

a = 4.4 m/s^2

Part f)

\theta = 333 degree

Explanation:

Part a)

Magnitude of tension force is given as

T = 757 N at 26.9 degree with vertical

T = 757 sin26.9 \hat i + 757 cos26.9 \hat j

T = 342.5 \hat i + 675\hat j

Part b)

Net force on Tarzen is given as

F_{net} = T + F_g

F_{net} = 342.5 \hat i + 675\hat j - 849 \hat j

F_{net} = 342.5\hat i - 174\hat j

Part c)

magnitude of the force is given as

F = \sqrt{F_x^2 + F_y^2}

F = \sqrt{342.5^2 + 174^2}

F = 384.2 N

Part d)

Direction of the force is given as

tan\theta = \frac{F_y}{F_x}

tan\theta = \frac{-174}{342.5}

\theta = 333 degree

Part e)

Magnitude of the acceleration

a = \frac{F}{m}

m = \frac{849}{9.81} = 86.5 kg

tex]a = \frac{384.2}{86.5}[/tex]

a = 4.4 m/s^2

Part f)

Direction of acceleration is same as the direction of the force

\theta = 333 degree

6 0
3 years ago
Compared to microwaves, ultraviolet waves have ___________________________ frequency.
vampirchik [111]
I think its a higher frequency
4 0
3 years ago
Identify the step of meiosis
Nimfa-mama [501]

Answer:

Since cell division occurs twice during meiosis, one starting cell can produce four gametes (eggs or sperm). In each round of division, cells go through four stages: prophase, metaphase, anaphase, and telophase.

5 0
3 years ago
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