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tensa zangetsu [6.8K]

3 years ago

6

Which statement about coal is true? When burned, coal produces pollutants that are released into the air. Coal will always stay

plentiful in the United States. Mining coal improves the environment. Burning coal does not pollute the air.

1 answer:

Svetllana [295]3 years ago

7 0

2, coal is a renewable resource

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Which sentence states Newton’s third law?

Katyanochek1 [597]

Each object exerts a force equal to and in the opposite direction of the other.

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3 years ago

Analyze the chemical reaction below

34kurt

Answer:

Please find the answer in the explanation.

Explanation:

Given that 16 g CH4 + 64 g 02 - 44 g CO2 + 36g H2O

To explain the law of conservation of mass and describe how the equation represents the law of conservation of mass, let me first start from law.

The law state that: mass can neither be created nor destroyed.

The mass of each element at the reaction side must be equal or the Same with the magnitude of mass at the product

The equation represents the law of conservation of mass because the mass of molecules at the right hand side is equal to or balance with the molecules at the left hand side. For example, the number of Oxygen, and othe elements are the at both side.

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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

A 1200 kg car accelerates from 13 m/s to 17 m/s. find the change in momentum of the car.

mixas84 [53]

P=4800kgm/s
As
p=mΔv
where p is momentum, m is mass and v is velocity
Given values is
m =1200kg
Δv= 17m/s-13m/s=4m/s
Now
p=mΔv
p=(1200kg)*(4m/s)
p=4800kgm/s

8 0

2 years ago

The spectral distribution of the radiation emitted by a diffuse surface may be approximated as follows. HW 2 Q2 (a) What is the

Ronch [10]

Answer:

a)<em> 2000 W/m² </em><em>; </em>b) 636.94 W/m<em>².sr ; </em><em>c) </em>0.5

Explanation:

a)

The formula for calculation of total emissive power is:

Total emissive power = E = $\int\limits^\alpha_0$ E'<em>λdλ</em>

<em> </em>= $\int\limits^a_0$ (0)d<em>λ + </em> $\int\limits^b_a$ (100)d<em>λ + </em> $\int\limits^c_b$ (200)d<em>λ + </em> $\int\limits^d_c$ (100)d<em>λ </em> $\int\limits^e_d$ (0)d<em>λ</em>

<em>where a = 5; b = 10; c = 15; d = 20; e = 25</em>

<em> = 0 +100(10-5) + 200(15-10) +100(20-15) + 0</em>

<em> = 2000 W/m²</em>

b)

The formula for total intensity of radiation is:

I $_{e}$ = E/π = 200/3.14 = 636.94 W/m<em>².sr </em>

<em>c)</em>

Fo submissive power leaving the surface in range π/4 ≤θ≤π/2

[E(π/4 ≤θ≤π/2)]/E = $\int\limits^f_0$ $\int\limits^g_0$ $\int\limits^i_h$ Icosθsinθ dθdΦdλ

where f = infinity, g=2π, h=π/4, i=π/2

By simplifying, we get

= (-1/2)[cos(2π/2)-cos(2π/2)]

= -0.5(-1-0)

=0.5

8 0

3 years ago