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barxatty [35]
3 years ago
9

"One of the main projects being carried out by the Hubble Space Telescope is to measure the distances of galaxies located in gro

ups dozens of millions of lightyears away. What method do astronomers use with the Hubble to find such distances
Physics
1 answer:
pickupchik [31]3 years ago
5 0

Answer:

finding Cepheid variable and measuring their periods.

Explanation:

This method is called  finding Cepheid variable and measuring their periods.

Cepheid variable is actually a type of star that has a radial pulsation having a varying brightness and diameter. This change in brightness is very well defined having a period and amplitude.

A potent clear link between the luminosity and pulsation period of a Cepheid variable developed Cepheids as an important determinants of cosmic criteria for scaling galactic and extra galactic distances. Henrietta Swan Leavitt revealed this robust feature of conventional Cepheid in 1908 after observing thousands of variable stars in the Magellanic Clouds. This in fact turn, by making comparisons its established luminosity to its measured brightness, allows one to evaluate the distance to the star.

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There is a very slight change in gravity at the top of a mountain. Which property
son4ous [18]

Answer:

The entity that decreases is the Weight.

Explanation:

Every object on the surface of the earth is usually pulled downwards by the action of gravity. The force or weight is W = mg

Now, the farther one gets away from the surface of the earth by climbing a mountain, the further the person is from the Earth's centre of gravity.

We know that the formula for Force of gravity away from the Earth's surface is given by;

F_g = GM1M2/r²

So the greater the distance, the lesser the gravitational force.

Now, the gravitational force equals the weight of the individual.

Thus, the entity that decreases is the Weight of the individual.

8 0
2 years ago
Pick 3 safety rules in science that you think are important and explain what would happen if the rules were no followed. Used yo
IgorLugansk [536]

Answer:

Answer down below!

Explanation:

  1. Always wear goggles! This is to prevent chemicals or any other substance to get into your eyes. If this wasn't followed, more people could get hurt.
  2. Clean up afterwards! Its always better to clean up so someone else couldn't get hurt! If people don't follow this, it could be a mess and someone could get seriously injured.
  3. When smelling something, waft it to your face, and not get real close. This is to prevent getting chemicals into your body that could be poisonous. If people didn't folloe this, someone could be seriously sick.
7 0
3 years ago
Transverse waves are being generated on a rope under constant tension. By what factor is the required power increased or decreas
ICE Princess25 [194]

Answer:

a) when the length of the rope is doubled and the angular frequency remains constant: The power increases by factor of two

b) when the amplitude is doubled and the angular frequency is halved: The power is the same

c) when both the wavelength and the amplitude are doubled: The power increases by a factor of 8

d) when both the length of the rope and the wavelength are halved: The power increases by factor of two

Explanation:

For a sinusoidal mechanical wave (Transverse wave), the time-averaged power is the energy associated with a wavelength divided by the period of the wave.

P_{avg} =\frac{E \lambda}{T}=\frac{1}{2} \mu A^2 \omega^2 \frac{\lambda}{T}

where;

A is the Amplitude

ω is the angular frequency

λ is the wavelength

a) when the length of the rope is doubled and the angular frequency remains constant

L = λ/2,  λ = 2L

The power increases by factor of two

b) when the amplitude is doubled and the angular frequency is halved

P_{avg} ={\frac{1}{2} \mu (2A)^2 (\frac{\omega}{2}) ^2 \frac{\lambda}{T} =  \frac{1}{2} \mu A^2 \omega^2 \frac{\lambda}{T}

The power is the same

c) when both the wavelength and the amplitude are doubled

P_{avg} =\frac{1}{2} \mu (2A)^2 \omega^2 \frac{(2\lambda)}{T} = \frac{1}{2} \mu (4A^2) \omega^2 \frac{(2\lambda)}{T} = 8 (\frac{1}{2} \mu A^2 \omega^2 \frac{\lambda}{T})

The power increases by a factor of 8

d) when both the length of the rope and the wavelength are halved

L = λ/2

when both are halved

L/2 =  λ/4, λ = 2L

The power increases by factor of two

8 0
3 years ago
The mass number of a neutral atom of potassium (z=19) is 40 How many electrons does it have?
BlackZzzverrR [31]

Answer:

Explanation:

Two

The nuclear force does not work

under long distances

is greater in strength the the electomagnetic force when the distances are small.

I'm not sure what D means.

I think it does depend on charge.

You have to choose D but this is a notes question and I'm not at all certain of the answer.

One

If its number is 19, the the number of protons = the number of electrons = 19

Answer B

7 0
3 years ago
Explain why generators are an important use of electromagnets.
alisha [4.7K]
A generator is a tool that is used in generating electriity. It converts mechanical energy into electrical energy in order to be used in an external circuit. The motors used for the conversion of energy contains a wire coil that is in a magnetic field. This wire coil is being used as a motor or as a generator. Using it as a generator, the wire coil should be spun results to inducing a current in the coil. When a wire coil is being spun in magnetic field, an AC electricity at constant rate is being produced which is then used by an external circuit. Generators are especially important during times of black out and lack of electricity supply from providers.
8 0
3 years ago
Read 2 more answers
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