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4 years ago

What would be the best method for a scientist to use in order to obtain a precise measurement of star’s distance from Earth?

2 answers:

8 0

D.). Radial Method - is the stars, and planets, that orbit around a common center of mass, The star will move towards, and away from earth. Light is shifted, as the star motion changes.

C.). Redshift Method - is described as, how light shifts toward shorter, or longer wavelengths; as objects in space, move closer, or farther away from us. If the star is moving away from us, The light it gets stretched a little, which makes it appear more red than it really is.

B.). Blueshift Method - is the opposite of redshift, its' a decrease in wavelength, due to its' motions towards Earth. If a star is moving closer to us, the light it gives off gets squeezed together, which makes it appear bluer than it actually is.

A.). Triangulation Method - is a method used to determine distances through parallax; The distance equals baseline divides by parallax. It is used to calculate stellar distances by using Earth's orbital diameter, as baseline, the angular displacement of a star is measured.

Therefore, Your answer: Letter Choice (A), Triangulation Method.

Hope that helps, (Answer: Letter Choice (A), Triangulation Method is used to obtain a precise measurement of a star's distance from Earth.).

Have a great day!!!!! : )

elena-s [515]4 years ago

6 0

Answer:

triangulation method

Explanation:

The triangulation method is used in Astronomy to measure distances of planets and nearby stars. To measure distances from distant stars in our galaxy, or other galaxies, we have to resort to indirect methods. For this reason, we can conclude that the triangulation method is the best method among those cited for a scientist to use to obtain an accurate measure of the distance between a star to Earth

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How does light from a headlamp use a lens and a mirror to produce a narrow beam?

Kryger [21]

The headlamp's concave mirror is open on one end, and the light bulb's filament is placed at or near the focus. (Sorry if this is Wrong)

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2 years ago

Read 2 more answers

11) A man is on a 1/4 on a bridge. A train is coming the same direction he is going. The man can run across the bridge in the sa

lesya692 [45]

15mph

If the man turns and runs toward point A, he will cover

3/8 of the length of the bridge in the time that it takes

the train to reach A.

If the man runs forward toward point B, what part of the bridge

will he cover before the train reaches A? Well, he will cover

3/8 of the bridge, only heading forward toward B. This will put

him 3/8 + 3/8 = 6/8 = 3/4 of the way across the bridge by the

time the train reaches A.

since we know that the man and the train will meet at B, this

means that in the time it takes the man to run the remaining

1/4 of the bridge, the train will cover the entire length of

the bridge.

If it takes the man the same time to cover 1/4 of the bridge

that it takes the train to cover the whole bridge, then the train

must be going four times as fast as the man. Another way of saying

this is that the man runs at 1/4 the speed of the train.

Since the train's speed is known to be 60 mph, this means that

the man runs at (1/4) 60 = 15 mph.

7 0

3 years ago

9. A 5.0 kg block on an inclined plane is acted upon by a horizontal force of 100 N shown in the figure below. The coefficient o

Helga [31]

Answer:

A: The acceleration is 7.7 m/s up the inclined plane.

B: It will take the block 0.36 seconds to move 0.5 meters up along the inclined plane

Explanation:

Let us work with variables and set

$m=5kg\\\\F_H=100N\\\\\mu=0.3\\\\\theta=37^o.$

As shown in the attached free body diagram, we choose our coordinates such that the x-axis is parallel to the inclined plane and the y-axis is perpendicular. We do this because it greatly simplifies our calculations.

Part A:

From the free body diagram we see that the total force along the x-axis is:

$F_{tot}=mg*sin(\theta)+F_s-F_Hcos(\theta).$

Now the force of friction is $F_s=\mu*N,$ where $N$ is the normal force and from the diagram it is $F_y=mg*cos(\theta).$

Thus $F_s=\mu*N=\mu*mg*cos(\theta).$

Therefore,

$F_{tot}=mg*sin(\theta)+\mu*mg*cos(\theta)-F_Hcos(\theta)\\\\=mg(sin(\theta)+\mu*cos(\theta))-F_Hcos(\theta).$

Substituting the value for $F_H,m,\mu, and \:\theta$ we get:

$F_{tot}= -38.63N.$

Now acceleration is simply

$a=\frac{F_H}{m} =\frac{-38.63N}{5kg} =-7.7m/s.$

The negative sign indicates that the acceleration is directed up the incline.

Part B:

$d=\frac{1}{2} at^2$

Which can be rearranged to solve for t:

$t=\sqrt{\frac{2d}{a} }$

Substitute the value of $d=0.50m$ and $a=7.7m/s$ and we get:

$t=0.36s.$

which is our answer.

Notice that in using the formula to calculate time we used the positive value of $a$ , because for this formula absolute value is needed.

5 0

4 years ago

Which term is defined by the force that moving, charged particles exert on one another?

Lisa [10]

Answer:

Electromagnetic force

Explanation:

There are four fundamental forces in nature:

- Gravity: it is the force that is exerted between any objects with mass. It is the weakest of all forces, so it is only relevant at planetary scales. It is always attractive, and it has an infinite range.

- Electromagnetic force: it is the force exerted between charged objects and between magnets (it is responsible for electric fields and magnetic fields). It is the 2nd strongest force, and it is the force that holds atoms in a molecule together. It can be attractive or repulsive, and it has an infinite range.

- Strong nuclear force: it is the strongest of all forces. It is responsible for holding the nucleons together inside the nucleus, and it is attractive. It has a very limited range ( $10^{-15}m$ ), so it is relevant only at very small scales

- Weak nuclear force: it is the force responsible for radioactive decays and neutrino interactions. It also has a very short range ( $10^{-18} m$

Looking at all these definitions, we see that the term that defines the force that acts between charged particles is the electromagnetic force.

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3 years ago

Which formula can be used to find the X component of the resultant vector?

julia-pushkina [17]

Answer:

If you are simply looking for the X component then the most applicable formula from the choices given is Tx + Ux+ Vx. This means that you will add all x-components. For example: If a man walking along the x-axis walks 10 meters to the right, 5 back and 2 meters forward, what is the resultant vector?

4 0

3 years ago