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2 years ago

What does the principle of the constancy of lightspeed tell us about the speed of light?

Physics

1 answer:

Thepotemich [5.8K]2 years ago

7 0

Answer:

The speed of light is not relative, it is always c no matter how fast or in what way the observer is moving

Explanation:

The speed of light. In a vacuum, it is by definition a universal constant of value 299,792,458 m / s (usually close to 3 · 108 m / s), or what is the same 9.46 · 1015 m / year; The second figure is used to define the interval called the light year. It is symbolized by the letter c, from the Latin celéritās (in Spanish celerity or rapidity), and is also known as the Einstein constant. [Citation needed] The value of the speed of light in a vacuum was officially included in the System International Units as a constant on October 21, 1983, thus passing the meter to be a unit derived from this constant. The speed through a medium other than the "vacuum" depends on its electrical permittivity, its magnetic permeability, and other electromagnetic characteristics. In material media, this speed is lower than "c" and is encoded in the index of refraction. In more subtle vacuum modifications, such as curved spaces, Casimir effect, thermal populations or presence of external fields, the speed of light depends on the energy density of that vacuum .

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A hydrogen discharge lamp emits light with two prominent wavelengths: 656 nm (red) and 486 nm (blue). The light enters a flint-g

mezya [45]

Answer:

The angle between the red and blue light is 1.7°.

Explanation:

Given that,

Wavelength of red = 656 nm

Wavelength of blue = 486 nm

Angle = 37°

Suppose we need to find the angle between the red and blue light as it leaves the prism

$n_{r}=1.572$

$n_{b}=1.587$

We need to calculate the angle for red wavelength

Using Snell's law,

$n_{r}\sin\theta_{i}=n_{a}\sin\theta_{r}$

Put the value into the formula

$1.572\sin37=1\times\sin\theta_{r}$

$\theta_{r}=\sin^{-1}(\dfrac{1.572\sin37}{1})$

$\theta_{r}=71.0^{\circ}$

We need to calculate the angle for blue wavelength

Using Snell's law,

$n_{b}\sin\theta_{i}=n_{a}\sin\theta_{b}$

Put the value into the formula

$1.587\sin37=1\times\sin\theta_{b}$

$\theta_{b}=\sin^{-1}(\dfrac{1.587\sin37}{1})$

$\theta_{b}=72.7^{\circ}$

We need to calculate the angle between the red and blue light

Using formula of angle

$\Delta \theta=\theta_{b}-\theta_{r}$

Put the value into the formula

$\Delta \theta=72.7-71.0$

$\Delta \theta=1.7^{\circ}$

Hence, The angle between the red and blue light is 1.7°.

8 0

2 years ago

If a calorie is equivalent to 4.184 joules how many joules are contained in 250 kg calories slice of pizza

Andreyy89

In order to answer this, we will set up a simple ratio as such:

1 calorie = 4.184 joules

1 kilocalorie = 1000 calories

1 kilocalorie = 4,184 joules

250 kilocalories = x joules

Cross multiplying the second and third equations, we get:

x joules = 4,184 * 250

250 kilocalories are equivalent to 1,046 kJ

6 0

2 years ago

If two vectors are perpendicular to each other, how should you add them?

Aleksandr [31]

Let us consider two vectors A and B.

As per the question, the two vectors are perpendicular to each other.

Hence the angle between them $\theta =90 degree$

We are asked to calculate the resultant of these two vectors.

As per parallelogram law of vector addition, the resultant of two vectors are-

$R=\sqrt{A^{2}+ B^{2}+2ABcos\theta$

$=\sqrt{ A^{2}+ B^{2}+2AB*cos90}$ [cos90=0]

$=\sqrt{ A^{2}+ B^{2}$

This is the way by which we can add two perpendicular vectors.

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3 years ago

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irga5000 [103]

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2 years ago

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Can a falling object reach terminal velocity in outer space? Explain.

Damm [24]

Ith air resistance acting on an object that has been dropped, the object will eventually reach a terminal velocity, which is around 53 m/s (195 km/h or 122 mph) for a human skydiver. ... (On the Moon, the gravitational acceleration is much less than on Earth, approximately 1.6 m/s2.)

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2 years ago