A star is moving toward the earth at 250 km/s. What can you say about the wavelength of the h-alpha absorption line that you would detect in the star's spectrum?

Answer:

6km

Explanation:

3hours X 2km = 6 kilometres

Answer:

Joule’s law of heating states that when a current ‘i ' passes through a conductor of resistance ‘r’ for time ‘t’ then the heat developed in the conductor is equal to the product of the square of the current, the resistance and time.

H = i 2 rt

The reason behind the heat produced is the collision of the free electrons with the lattice ions or atoms while accelerating in presence of the external electric field.

we know that

volt= work done/ total charge or v = w/q

from this we get w= vq

we know that current i = q / t

so q = it

putting this in prev equation

we get w = vit

from ohms law v = ir

putting it in prev eq we get

w = irit = i2rt joule as work is stored as heat soH = I2RT Joules

if a current carrying conductor having resistance (r) gets heated by to passing of current (i) for time (t) and the heat thereby produced be H

joules law states that

H propotional to i^ 2 when r and t are constant

H propotional to r when I and t are constant

H propotional to t when r and I constant

Answer:

True

Explanation:

It is TRUE that Motion and acceleration may only be used to refer to physical objects moving or changing speed/direction.

This is because if an object is not moving or changing speed/direction to a determined point of reference, the object is considered to be at rest or motionless, thereby, with no absolute point of reference, absolute motion or acceleration cannot be distinguished.

Explanation:

the speed of the dog was 400

Answer:

ITU Sangat bermanfaaat

Answer:

True.

Explanation:

One can expect good quality produce if proper attention is given to the proper selection of planting materials.

Lithium fluoride will be most soluble in water because it is most strongly ionic.

Solubility is the amount of a substance that dissolves in a given volume of solvent at a particular temperature.

Solubility is affected by:

Water is a polar molecule.

Lithium fluoride will be most soluble in water because it is most strongly ionic.

Learn more about solubility at: https://brainly.com/question/23946616

Answer:

the girl's displacement in both magnitude and direction is 7.81 m at 50.2⁰ North west.

Explanation:

Given;

6km due west, and

5km due north

The magnitude of her displacement is calculated by forming a right angled triangle. The hypotenuse side of the triangle is the girl's displacement.

d² = 5² + 6²

d² = 25 + 36

d² = 61

d = √61

d = 7.81 m

The direction of the girl is calculated as;

[tex]tan \ \theta = \frac{6}{5} \\\\tan \ \theta = 1.2\\\\\theta = tan^{-1} (1.2)\\\\\theta = 50.2^0[/tex]

Therefore, the girl's displacement in both magnitude and direction is 7.81 m at 50.2⁰ North west.

Answer: B) Frequency

Explanation:

The orientation of the magnets that gives the strongest repulsion because these poles and facing each other that is then leaves highest flux density of the poles for a force of repulsion to be very high

Answer:

c. dioptre that's the answer.

Answer:

Explanation:

We shall find first the distance where electric field is E/4 .

Let the charge be Q and distance be d where electric field is E . From the coulomb's Law

E = k Q / d²

Let distance be d₁ where field is E/4

E/4 = kQ / d₁²

Dividing the two equation

4 = d₁² / d²

d₁ = 2d

We shall have to find Potential at d₁ which is equal to 2 d .

Potential at d₁

V = k Q / 2d

= kQ d / 2d²

= E d / 2 . where d is distance of the point where field is E .

Answer:

V=14

Explanation:

PE=KE

mgh=1/2mv^2

(2)(9.8)(10)=1/2(2)v^2

(radical) 196=(radical) v

V=14

Answer:

Generally, by wavelengths and frequencies.

Colors only occur for a narrow portion of the spectrum.

The speed for these waves is c the speed of light regardless of wavelength.

The way they are used seems somewhat irrelevant.

The electromagnetic spectrum is divided into regions by wavelengths and frequencies. The spectrum is arranged in the order of increasing frequency.

The electromagnetic spectrum is the arrangement of waves in  the  order increasing frequency or decreasing wavelength. The order of the spectra starts from radio waves, microwaves, infrared, visible light, ultraviolet, x -rays and gamma rays.

The visible light that we can see is in between IR and UV rays. Hence, visible light has a frequency greater than IR rays but shorter than IR. Similarly visible light is longer than UV- rays but less frequency than UV rays.

Gamma  rays are the most energetic and shorter waves in the electromagnetic spectrum with smaller wavelength and greater frequency. Hence, options a is correct.

Find more on electromagnetic waves:

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Answer:

895522 times faster.

Explanation:

From the question given above, the following data were obtained:

Speed of sound in air (v) = 335 m/s

Speed of light in air (c) = 3×10⁸ m/s

How many times faster =.?

To obtain how many times faster light travels in air than sound, do the following

c : v => 3×10⁸ : 335

c/v = 3×10⁸ / 335

c/v = 895522

Cross multiply

c = 895522 × v

From the illustrations made above, we can see that the speed of the light in air (c) is 895522 times the speed of sound in air.

Thus, light travels 895522 times faster than sound in air.

Answer:

DNA contains the instructions needed for an organism to develop, survive and reproduce. To carry out these functions, DNA sequences must be converted into messages that can be used to produce proteins, which are the complex molecules that do most of the work in our bodies

Answer:

You take the basic formula of E = I x R, solve for R -> R = E / I. In other words, take the required voltage drop (in volts) and divide by the current (in amps) in the resistor and determine the resistance (R) in ohms.

Explanation: hope this helps

Answer:

8 N

Explanation:

The force between two charges is given by :

[tex]F=\dfrac{kq_1q_2}{d^2}[/tex]

Where

k is electrostatic constant

d is the distance between two charges

It means,

[tex]F\propto \dfrac{1}{d^2}[/tex]

When the distance is d, the force is 2 N. If the charge on each sphere is doubled, q₁' = q₂' = 2q₁ = 2q₂. New force will becomes:

[tex]F'=\dfrac{kq_1'q_2'}{d^2}\\\\F'=\dfrac{k2q_1\times 2q_2}{d^2}\\\\F'=4\times \dfrac{kq_1q_2}{d^2}\\\\F'=4\times 2\\\\F'=8\ N[/tex]

So, the new force becomes 8N. Hence, the correct option is (d).

Answer:

B

Explanation:

this is because the neutrons do not have a charge, the things that have charge in an atom are electrons and protons.

and in the nucleus of an atom, there are protons and neutrons so you can see that A is not the answer

if you see the periodic table, you will know that the number of electrons and protons are equal, so the charges cancel each other out, hence the charge of an atom will be neutral

let me give you a tip which I got from my teacher, never write there is no charge in the atom, this suggests that there is no protons or electrons.

instead, write, the it is neutral

hope it helps if not please report it so that someone else gets to try it out

Answer:

5.17 x 10^5

Explanation

The correct answer is (b) [tex]5.17*10^{5}m[/tex]

Let us consider an object of mass m on the planet Q.

On planet Q, let the acceleration due to gravity be g = 2.24 m/[tex]s^{2}[/tex]

Mass of the planet is M = [tex]8.96*10^{21} kg[/tex]

Let its radius be R

and the universal gravitational constant G = [tex]6.67*10^{-11} m/kg[/tex]

Gravitational Force acting on the object:

[tex]mg=\frac{GMm}{R^{2} }[/tex]

[tex]R=\sqrt{\frac{GM}{g} } \\R=\sqrt{\frac{6.67*10^{-11}*8.96*10^{21} }{2.24} }\\R=5.17*10^{5} m[/tex] is the radius of the planet Q.

Learn more about gravitational force:

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Answer:

≈ 22 seconds

Explanation:

7,5 km = 7500 m

Speed of light 300 000 000 m/s (for lightning)

Speed of sound 343 m/s (for thunder)

time = distance / speed

lightning time = 7500 m / 300 000 000 m/s = 0.000025 s

thunder time = 7500 m / 343 m/s ≈ 22 s

thunder time - lightning time = 22 s - 0.000025 s ≈ 22 s

Answer:

I believe the answer is B.)

Answer:

urjshsus uevus e survey dydvd dydvdyd d dgdv gdyr yrgdvv yth yrhvthr

Explanation:

ydgdydvd yd dv ydvr dyve dysdvdyr gdvr

Answer:

Here is your ans

Explanation:

hope it helps you tq

Answer:

4 × 5 = 5 + 5 + 5 + 5 = 20

Explanation:

Pick one factor and add it.

Answer:

Electrolytic manganese dioxide (EMD) is used in zinc-carbon batteries together with zinc chloride and ammonium chloride. EMD is commonly used in zinc manganese dioxide rechargeable alkaline (Zn RAM) cells also. For these applications, purity is extremely important.

Explanation:

hope this helps...

Answer:

1. thermal energy

2. Batteries and coal

4. energy conversion

Answer:

- 42

Explanation:

m = 6kg

vi = 17 m/s

vf = 10 m/s

delta mv = ?

Formula

delta mv = m*(vf) - m(vi)

delta mv = 6(10 - 17)

delta mv = 6(-7)

delta mv = - 42 kg m/s

Answer:

Unsaturated

Explanation:

the solubility of sodium nitrate is at 60 C is 124g/ml therefore, putting 100 grams will not saturate fully.