A bag of firewood has a mass of 10.0 kilograms and a weight of

Explain how astronomers might use spectroscopy to determine the composition and temperature of a star.

Damm [24]

Everything starts from spectroscopy. Astronomers only have concentrated information at wavelengths that are emitted from the stars. What they do with this information is to obtain the frequency range of the stars and through spectroscopes they are responsible for dividing the radiation beams and determining the coincidence with the emission of those same waves, of chemical elements. From these observation techniques it is possible to obtain the composition and according to the color, obtaining characteristics such as temperature. The spectrum of stars consists of dark and bright lines called Fraunhofer lines. This spectrum is compared to the spectrum of different elements to find the composition of the stars. This is possible because the elements emit or absorb only specific wavelengths.

4 0

3 years ago

The potential difference between the surface of a 3.0-cm-diameter power line and a point 1.0 m distant is 3.9 kV. Find the line

Korolek [52]

Answer:

The linear charge density is 5.19 X 10⁻⁶ C/m

Explanation:

The potential difference between two cylinders, is given as

V = (λ/2πε)ln(b/a)

where;

λ is the line charge density on the power line.

b is the distance between the power line = 1 m

a is the radius of the wire = 1.5 cm = 0.015 m

ε is the permittivity of free space = 8.9 X 10⁻¹² C

V*2πε = λ* ln(b/a)

3900 *(2π*8.9 x10⁻¹²)= λ *ln(1/0.015)

2.1812 X 10⁻⁷ = 4.1997* λ

λ = 5.19 X 10⁻⁶ C/m

Therefore, the linear charge density is 5.19 X 10⁻⁶ C/m

6 0

3 years ago

Solenoid (a) has twice the diameter, three times the length, and four times the number of turns of solenoid (b). The two solenoi

Cloud [144]

Answer:

family They don't want them . There was a lady from there neighborhood can't bearer she said I can Take care of them . She was multi Millionaire she changed their names and she brought for them bed rooms ، bathroom and thire on toy's And a special clothing . they lived with her only 5 years then she said for the oldest daughter

step mom :mickey be careful with your siblings

Mikinzy : what will happen

Step mom: only I am telling you

After 2 weeks the step mother gaved the maid and told her.

Step mother: this is 3 millions for the kids and take care of them and don't tell them that I am traveling .

Maid : and if they asked me

step mother : she went to her family 5 months only .

Maid: but where you are going madame

Step mother: actually I am going to do a surgery in london

Maid : but why

Step mother: because I can't beCome

Pregnant

Maid: but you have mikinzy kareem and natalie

Step mother: it's not your problem so go away from my face

After 2 weeks mikinzy asked the maid where is my mother the maid told her everything mikinzy started to cry the maid went to her room

Maid mikinzy open the door I want to tell you something but I don't want natalie and kareem hear us

Mikinzy opened the door

Maid : I want to tell you something I love you and I hope to have only one daughter like You

Mikinzy : can you be my mother

Then the maid sell everything was at the castle and She said to mikinzy I will buy another castle to live there and buy our furniture mikinzy liked her idea after that mikinzy got bigger and studied medicine and became a doctor and her sister natalie studied special needs education and kareem became Engineer and they stayed with their maid actually there mom .

Explanation:

family They don't want them . There was a lady from there neighborhood can't bearer she said I can Take care of them . She was multi Millionaire she changed their names and she brought for them bed rooms ، bathroom and thire on toy's And a special clothing . they lived with her only 5 years then she said for the oldest daughter

step mom :mickey be careful with your siblings

Mikinzy : what will happen

Step mom: only I am telling you

After 2 weeks the step mother gaved the maid and told her.

Step mother: this is 3 millions for the kids and take care of them and don't tell them that I am traveling .

Maid : and if they asked me

step mother : she went to her family 5 months only .

Maid: but where you are going madame

Step mother: actually I am going to do a surgery in london

Maid : but why

Step mother: because I can't beCome

Pregnant

Maid: but you have mikinzy kareem and natalie

Step mother: it's not your problem so go away from my face

After 2 weeks mikinzy asked the maid where is my mother the maid told her everything mikinzy started to cry the maid went to her room

Maid mikinzy open the door I want to tell you something but I don't want natalie and kareem hear us

Mikinzy opened the door

Maid : I want to tell you something I love you and I hope to have only one daughter like You

Mikinzy : can you be my mother

Tqnzy liked her idea after that mikinzy got bigger and studied medicine and became a doctor and her sister natalie studied special needs education and kareem became Engineer and they stayed with their maid actually there mom .

3 0

3 years ago

A 75 kg baseball player runs at a velocity of 6 m/s before sliding to a stop at second base. a. What is the kinetic energy of th

lana [24]

Answer:

a. $\displaystyle k_o=1350\ J$

b. $\displaystyle k_1=0\ J$

c. $\Delta k=-1350\ J$

d. $W=-1350\ J$

e. $F=-675\ N$

Explanation:

<u>Work and Kinetic Energy </u>

When an object moves at a certain velocity v0 and changes it to v1, a change in its kinetic energy is achieved:

$\Delta k=k_1-k_0$

Knowing that

$\displaystyle k=\frac{mv^2}{2}$

We have

$\displaystyle \Delta k=\frac{mv_1^2}{2}-\frac{mv_0^2}{2}$

The work done by the force who caused the change of velocity (acceleration) is

$\displaystyle W=\frac{mv_1^2}{2}-\frac{mv_0^2}{2}$

If we know the distance x traveled by the object, the work can also be calculated by

$W=F.x$

Being F the force responsible for the change of velocity

The 75 kg baseball player has an initial velocity of 6 m/s, then he slides and stops

a. Before the slide, his initial kinetic energy is

$\displaystyle k_o=\frac{mv_0^2}{2}$

$\displaystyle k_o=\frac{(75)6^2}{2}$

$\boxed{\displaystyle k_o=1350\ J}$

b. Once he reaches the base, the player is at rest, thus his final kinetic energy is

$\displaystyle k_1=\frac{(75)0^2}{2}$

$\boxed{\displaystyle k_1=0\ J}$

c. The change of kinetic energy is

$\Delta k=k_1-k_0=0\ J-1350\ J$

$\boxed{\Delta k=-1350\ J}$

d. The work done by friction to stop the player is

$W=\Delta k=k_1-k_0$

$\boxed{W=-1350\ J}$

e. We compute the force of friction by using

$W=F.x$

and solving for x

$\displaystyle F=\frac{W}{x}$

$\displaystyle F=\frac{-1350\ J}{2\ m}$

$\boxed{F=-675\ N}$

The negative sign indicates the force is against movement

6 0

3 years ago

Define a method pyramidVolume with double parameters baseLength, baseWidth, and pyramidHeight, that returns as a double the volu

lara31 [8.8K]

Answer:

Explanation:

Its not a good practice to write all the functions including main() in the same class.

But as you opted for this, the code goes here like this:

public class CalcPyramidVolume {

/* Your solution goes here */

static double pyramidVolume(double baseLength, double baseWidth, double pyramidHeight)

{

double Volume,baseArea;

baseArea = baseLength * baseWidth;

Volume = baseArea * pyramidHeight * 1/3;

return Volume;

}

public static void main (String [] args) {

System.out.println("Volume for 1.0, 1.0, 1.0 is: " + pyramidVolume(1.0, 1.0, 1.0));

return;

}

And there is not caveat of integer division, as you are declaring all your variables of type double.

3 0

4 years ago

Read 2 more answers