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1 year ago

What is the energy (in evev) of a photon of visible light that has a wavelength of 500 nmnm?

Physics

1 answer:

lisabon 2012 [21]1 year ago

6 0

<h3>Answer:</h3>

E≈2,5 eV

<h3>Explanation:</h3>

_______________

λ=500 nm = 500·10⁻⁹ m

c=3·10⁸ m/s

h=6,63·10⁻³⁴ J·s = 4,14·10⁻¹⁵ eV·s

_______________

E - ?

_______________

$\displaystyle \boldsymbol{E}=h\nu =h \frac{c}{\lambda} =4,14\cdot 10^{-15} \; eV\cdot s\cdot \; \frac{3\cdot 10^8\; m/s}{500\cdot 10^{-9}\; m} =2,484\; eV\approx \boldsymbol{2,5\; eV}$

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Generate description of the right hand rule for finding the magnetic field around a current carrying wire an tell how it is used

vladimir1956 [14]

Answer:

Right hand thumb rule : It is a rule used to find the magnetic field direction around current carrying wire .

Explanation:

It states that : "If you grasp conductor in your right hand such that thumb points in upward direction ,then the direction in which our finger curls gives the direction of magnetic field or magnetic lines of forces" .

This rule proves that :Current can give rise to magnetism .

Around every current carrying conductor there exist a magnetic field which can be easily felt .

According to this rule : When a current flows in upward direction ,the finger curls in anticlockwise direction and when direction of current reverses ,then the direction of field also reverses .

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3 years ago

If Star A is magnitude 1.0 and Star B is magnitude 9.6 , which is brighter and by what factor?

ludmilkaskok [199]

Answer:

Star A is brighter than Star B by a factor of 2754.22

Explanation:

Lets assume,

the magnitude of star A = m₁ = 1

the magnitude of star B = m₂ = 9.6

the apparent brightness of star A and star B are b₁ and b₂ respectively

Then, relation between the difference of magnitudes and apparent brightness of two stars are related as give below: $(m_{2} - m_{1}) = 2.5\log_{10}(b_{1}/b_{2})$

The current magnitude scale followed was formalized by Sir Norman Pogson in 1856. On this scale a magnitude 1 star is 2.512 times brighter than magnitude 2 star. A magnitude 2 star is 2.512 time brighter than a magnitude 3 star. That means a magnitude 1 star is (2.512x2.512) brighter than magnitude 3 bright star.

We need to find the factor by which star A is brighter than star B. Using the equation given above,

$(9.6 - 1) = 2.5\log_{10}(b_{1}/b_{2})$

$\frac{8.6}{2.5} = \log_{10}(b_{1}/b_{2})$

$\log_{10}(b_{1}/b_{2}) = 3.44$

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$(b_{1}/b_{2}) = 2754.22$

It means star A is 2754.22 time brighter than Star B.

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3 years ago

In a fireworks display, a rocket is launched from the ground with a speed of 18.0 m/s and a direction of 51.0° above the horizon

Masja [62]

Answer:38.66 m

Explanation:

Given

launch angle $\theta =51^{\circ}$

launch velocity $u=18 m/s$

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$R=\frac{u^2\sin 2\theta }{g}$

$R=\frac{18^2\sin 102}{9.8}$

$R=32.33 m$

Center of mass will be at $x=32.33 m$

(b)if one of the piece will be at x=26 m then other will be at

$x_{com}=\frac{m_1x_1+m_2x_2}{m_1+m_2}$

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2 years ago

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Marina CMI [18]

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2 years ago

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Scilla [17]

I hope the answer is D. Pressure

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2 years ago

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