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3 years ago

Explain what dispersion is and how astronomers use this phenomenon to study a star’s light.

Physics

1 answer:

My name is Ann [436]3 years ago

6 0

Answer:

Splitting of light in seven different colors showing the complete spectrum is known as dispersion.

Explanation:

The visible part of the complete EM spectrum, visible light, is made up of seven different colors (Acronym: VIBGYOR). When visible light beam is passed through a prism or diffraction grating it splits into 7 different colors, this process is known as dispersion. The band of 7 colors is called as Spectrum of light.

Every element shows a different spectrum. When we study the spectrum of a compound we can get to know which all elements are present inside it. This technique is known as Spectroscopy.

The same technique is used to study the composition of stars. Astronomers study the spectrum of light coming from the stars to know the elements present inside them. Along with that we can also find out the relative motion of stars using the Doppler's effect. We can get to know whether an object is moving towards or away from us by studying its spectrum.

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Whenever an object is moving at a constant rate, the value(s) that equal zero is (are):

dolphi86 [110]

Answer:

d) all of the above

Explanation:

the speed, velocity, and acceleration all changes to 0 due to no motion.

5 0

3 years ago

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Microwave ovens use microwave radiation to heat food. the microwaves are absorbed by the water molecules in the food, which is t

PIT_PIT [208]

<span>step 1: energy required to heat coffee E = m Cp dT E = energy to heat coffee m = mass coffee = 225 mL x (0.997 g / mL) = 224g Cp = heat capacity of coffee = 4.184 J / gK dT = change in temp of coffee = 62.0 - 25.0 C = 37.0 C E = (224 g) x (4.184 J / gK) x (37.0 C) = 3.46x10^4 J step2: find energy of a single photon of the radiation E = hc / Î» E = energy of the photon h = planck's constant = 6.626x10^-34 J s c = speed of light = 3.00x10^8 m/s Î» = wavelength = 11.2 cm = 11.2 cm x (1m / 100 cm) = 0.112 m E = (6.626x10^-34 J s) x (3.00x10^8 m/s) / (0.112 m) = 1.77x10^-16 J step3: Number of photons 3.46x10^4 J x ( 1 photon / 1.77x10^-16 J) = 1.95x10^20 photons</span>

7 0

3 years ago

Read 2 more answers

Grindstone: Rotational Dynamics and Kinematics You have a grindstone (a disk) that is 133.0 kg, has a 0.635 m radius, and is tur

Colt1911 [192]

Answer:

Ff = 839.05 N

Explanation:

We can use the equation:

Ff = μ*N

where <em>N</em> can be obtained as follows:

∑ Fc = m*ac ⇒ N - F = m*ac = m*ω²*R ⇒ N = F + m*ω²*R

then if

F = 32 N

m = 133 Kg

R = 0.635 m

ω = 95 rev /min = (95 rev / min)(2π rad / 1 rev)(1 min / 60 s) = 9.9484 rad /s

we get

N = 32 N + (133 Kg)*(9.9484 rad /s)²*(0.635 m) = 8390.53 N

Finally

Ff = μ*N = 0.10*(8390.53 N) = 839.05 N

3 0

3 years ago

Which of the following statements about iron filings placed upon glass resting on top of a bar magnet is false?

leva [86]

The answer would be D. Because the iron fillings are attracted to the magnet underneath the glass.

5 0

2 years ago

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Assume that the function x(t) represents the length of tape that has unwound as a function of time. find θ(t), the angle through

bekas [8.4K]

We know that arc length (x(t)) is given with the following formula:
$x(t)=\theta(t) r$
Where r is the radius of the barrel. We must keep in mind that as barrel rolls its radius decreases because less and less tape is left on it.
If we say that the thickness of the tape is D then with every full circle our radius shrinks by d. We can write this down mathematically:
$r(\theta)=r_0-\frac{D\cdot \theta}{2\pi}$
When we plug this back into the first equation we get:
$x(t)=\theta(r_0-\frac{D\theta}{2\pi}})\\ \frac{D\theta^2}{2\pi}-\theta r_0+x(t)=0\\$
We must solve this quadratic equation.
The final solution is:
$\theta=\frac{\pi r_0+\sqrt{\pi \left(-2Dx(t)+\pi r_0^2\right)}}{D},\:\theta=\frac{\pi r_0-\sqrt{\pi \left(-2Dx(t)+\pi r_0^2\right)}}{D}$
It is rather complicated solution. If we asume that the tape has no thickness we get simply:
$x(t)=\theta(r_0-\frac{D\theta}{2\pi}});D=0\\
x(t)=\theta r_0\\
\theta(t)=\frac{x(t)}{r_0}$

8 0

3 years ago