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4 years ago

Which of the following cannot be determined from the spectrum of a star?

Physics

2 answers:

lozanna [386]4 years ago

7 0

Answer:

The chemicals in the core of the star

Explanation:

The spectrum of a star is of its atmosphere. The absorption or emission spectrum that is obtained indicates the chemical composition of the star's atmosphere. The peak wavelength obtained indicates the surface temperature of the star (using Wien's-Displacement Law). The shift in the spectrum indicates the motion of the star. If there is blueshift, it indicates that it is moving towards us where as if there is a red shift, it indicates that it is moving away from us.

grigory [225]4 years ago

4 0

The event that cannot be determined from the spectrum of a star is that the <span>chemicals in the atmosphere of the star</span>

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The weight of an object on a planet depends on not only its mass but also on its distance from the planest center. this table li

-BARSIC- [3]

Uranus is much much larger than Earth, so the distance from the planet's center is much much greater

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3 years ago

A roller coaster car may be approximated by a block of mass m. Thecar, which starts from rest, is released at a height h above t

elena55 [62]

Answer:

The first part can be solved via conservation of energy.

$mgh = mg2R + K\\K = mg(h-2R)$

For the second part,

the free body diagram of the car should be as follows:

- weight in the downwards direction

- normal force of the track to the car in the downwards direction

The total force should be equal to the centripetal force by Newton's Second Law.

$F = ma = \frac{mv^2}{R}\\mg + N = \frac{mv^2}{R}$

where $N = 0$ because we are looking for the case where the car loses contact.

$mg = \frac{mv^2}{R}\\v^2 = gR\\v = \sqrt{gR}$

Now we know the minimum velocity that the car should have. Using the energy conservation found in the first part, we can calculate the minimum height.

$mgh = mg2R + \frac{1}{2}mv^2\\mgh = mg2R + \frac{1}{2}m(gR)\\gh = g2R + \frac{1}{2}gR\\h = 2R + \frac{R}{2}\\h = \frac{5R}{2}$

Explanation:

The point that might confuse you in this question is the direction of the normal force at the top of the loop.

We usually use the normal force opposite to the weight. However, normal force is the force that the road exerts on us. Imagine that the car goes through the loop very very fast. Its tires will feel a great amount of normal force, if its velocity is quite high. By the same logic, if its velocity is too low, it might not feel a normal force at all, which means losing contact with the track.

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3 years ago

If an isotope has 8 protons and 10 neutrons in it's nucleus, what is it's atomic mass?

viva [34]

The atomic mass is always equal to the sum of protons and neutrons in the nucleus. If you add the number of protons and neutrons (8 + 10) = 18 you will find that the atomic mass is 18.

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3 years ago

The displacement of a wave traveling in the negative y-direction is D(y,t) = ( 4.60 cm ) sin ( 6.20 y+ 60.0 t ), where y is in m

trapecia [35]

Answer:

The question is incomplete, below is the complete question

"The displacement of a wave traveling in the negative y-direction is D(y,t) = ( 4.60cm ) sin ( 6.20 y+ 60.0 t ), where y is in m and t is in s.

A) What is the frequency of this wave?

B) What is the wavelength of this wave?

C) What is the speed of this wave?"

Answers:

a. $f=\frac{30}{\pi }Hz\\$