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4 years ago

Astar begins as a blank a large cloud of gas and dust

1 answer:

3 0

This is a statement but yes a star forms inside nebulae which are gigantic clouds of gas. stars form inside as the gases own gravity pulls it together after which it becomes large enough to perform fusion and become a star.

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Hola me pueden ayudar necesito los cuerpos de:

kumpel [21]

The answer is Madera

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3 years ago

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This is a change in an object's position. <br> Net Force<br> Gravitational Pull<br> Motion<br> Force

alexira [117]

Answer:

Motion

Explanation:

because when something moves its call motion

3 0

3 years ago

Which of the following expressions gives the ratio of the energy density of the magnetic field to that of the electric field jus

miss Akunina [59]

Answer:

$(d) \ \ \frac{\mu_o}{\epsilon_o} (\frac{L}{2\pi r*R} )^2$

Explanation:

Energy density in magnetic field is given as;

$U_B = \frac{1}{2 \mu_o} B^2$

where;

B is the magnetic field strength

Energy density of electric field

$U_E = \frac{1}{2}\epsilon E^2$

where;

E is electric field strength

Take the ratio of the two fields energy density

$\frac{U_B}{U_E} = \frac{1}{2\mu_o} B^2 / \frac{1}{2}\epsilon E^2\\\\\frac{U_B}{U_E} = \frac{B^2}{2\mu_o} *\frac{2}{\epsilon E^2} \\\\\frac{U_B}{U_E} = \frac{1}{\mu_o \epsilon} (\frac{B^2}{E^2})$

$\frac{U_B}{U_E} = \frac{1}{\mu_o \epsilon} (\frac{B}{E})^2$

But, Electric field potential, V = E x L = IR (I is current and R is resistance)

$\frac{U_B}{U_E} = \frac{1}{\mu_o \epsilon} (\frac{B*L}{E*L})^2$

Now replace E x L with IR

$\frac{U_B}{U_E} = \frac{1}{\mu_o \epsilon} (\frac{B*L}{IR})^2$

Also, B = μ₀I / 2πr, substitute this value in the above equation

$\frac{U_B}{U_E} = \frac{1}{\mu_o \epsilon} (\frac{\mu_oI*L}{2\pi r* IR})^2$

cancel out the current "I" and factor out μ₀

$\frac{U_B}{U_E} = \frac{\mu_o^2}{\mu_o \epsilon} (\frac{L}{2\pi r* R})^2$

Finally, the equation becomes;

$\frac{U_B}{U_E} = \frac{\mu_o}{\epsilon} (\frac{L}{2\pi r*R })^2$

Therefore, the correct option is (d) μ₀/ϵ₀ (L /R 2πr)²

3 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

For a sine wave depicting simple harmonic motion, the smaller the amplitude of the wave, the smaller the of the pendulum from th

stiks02 [169]

Displacement , shorter

7 0

4 years ago

Read 2 more answers