If star A is 20 light years away from earth and star B is 40 light years away from earth,which star appears brighter and by what factor?

Answers

Answer 1

Answer:

Because Star A and Star B have identical luminosities, the difference in their apparent brightness is due solely to distance. Star B is twice as far from Earth as Star A.

Explanation:


Related Questions

Most solar hot water systems are fitted with gas or electric "boosters" that can also heat the water.

Describe why you think these are necessary.

DUE IN 2 HOURS PLEASE HELP!!

Answers

To provide hot water on cloudy days or when demand exceeds supply, most solar water heaters come with a gas or electric booster. A gas booster usually produces fewer greenhouse gas emissions unless renewable electricity is used or the booster is a heat pump.

What is the value of acceleration as a body moves with an uniform speed

Answers

Answer:

the value of acceleration as a body moves with an uniform speed is zero

the scientist who gives the definition of work

Answers

Answer:

Work, in physics, measure of energy transfer that occurs when an object is moved over a distance by an external force at least part of which is applied in the direction of the displacement. ... To express this concept mathematically, the work W is equal to the force f times the distance d, or W = fd.

3. True or False: A warm-up can include minimal stretching at the end.

Answers

Answer:

False.

Explanation:

A warm up is stretching in the beginning.


A particular electric car is supplied with 300 kJ of chemical energy by the battery. Of this, a total of 70.5 kJ of energy is wasted as heat.
Calculate the overall efficiency of the electric car.

Answers

Supplied energy=300kJ

Wasted energy=70.5J

Used energy:-

[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]

We know

[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]

[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]

[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]

[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]

The overall efficiency of the electric car = 76.5 %

To find the efficiency the given values are:

Energy supplied = 300 kJ

Energy wasted = 70.5 kJ

Define efficiency and calculate the value of efficiency.

      In the system the output energy is compared to the input energy is known as efficiency. That can be written as percentage ratio of output energy to the input energy.

Formula of efficiency is,

             Efficiency = ( E out / E in ) × 100

Here, Energy supplied = 300 kJ

so, energy used = Energy supplied - Energy wasted

                           = 300 - 70.5

                           =  229.5 kJ

Thus, substituting E out = 300 kJ , E in = 229.5 kJ

            Efficiency = ( 229.5 / 300 ) ×100

                             = 229.5 / 3

                             = 76.5

Hence, The overall efficiency of the electric car is 76.5 %

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1. Car A is heading East at 25 m/s and car B is also heading East at 25 m/s. What is the relative velocity between car A
and car B? How would the passenger in Car A describe Car B's motion

Answers

The relative velocity between Car A and Car B is 0 m/s

Since Car A is heading East at 25 m/s, its velocity is u = + 25 m/s. (since it is moving in the positive x- direction)

Also, car B is also heading East at 25 m/s, its velocity is v = + 25 m/s. (since it is moving in the positive x- direction)

So, the relative velocity between car A and Car B is V = velocity of car A - velocity of car B.

So, V = u - v

V = + 25 m/s - (+ 25 m/s)

V = + 25 m/s - 25 m/s

V = 0 m/s

So, the relative velocity between Car A and Car B is 0 m/s

The passenger in Car A would describe Car B's motion as stationary.

Since Car A is heading East at 25 m/s and car B is also heading East at 25 m/s, both cars are moving at a velocity of + 25 m/s.

Since their relative velocity is 0 m/s, it would appear to a passenger in Car A that car B is stationary according to motion from car A's reference frame.

So, the passenger in Car A would describe Car B's motion as stationary.

Define measurement and write its importance.​

Answers

Answer:

Measurement is the way humans define certain amounts of matter, and is expressed in various types of units respective to the type of matter or object being defined.

Explanation:

Measurement is extremely important because it helps one another understand how much of something is needed to accomplish something. If no method existed to define the specific amount needed, we would simply mess delicate operations up and machines, even simple recipes, would fail.

Question 8(Multiple Choice Worth 2 points)

(05.06 MC)

Jon is designing an experiment to see the effect of mechanical energy on the number of times a ball bounces. Why is it important that Jon keeps detailed records of his experiment?

The records will show how bouncy the ball is.
The evidence produced by his experiment should be replicable by others.
The evidence produced by the experiment will prove that he is a good scientist.
The records will prove that the mechanical energy of the ball will change with height

Answers

Answer:

D

Explanation:

The answer is d dont worry about the comment sorry

Thiết bị nào sau đây không phải là nguồn điện
A. Ắc quy
B. Pin
C. Máy phát điện
D. Bóng đèn điện

Answers

shsbbsnsjsbsnsnsnsnsnsndndndnd

a teacher drives from school to the mall. then she goes to the doctors office for a physical examination. what is the magnitude of her displacement

Answers

The magnitude of the teachers displacement is the difference between

the location of the school and the location of the doctors office

The reason behind the above expression are explained as follows

The known locations of the teacher;

Initial location; The school

Second location; The mall

The eventual location; The doctors office

The required information;

The magnitude of the teachers displacement

The method of obtaining the displacement of the teacher;

Qualitatively, the displacement of the teacher can be obtained by applying the definition of displacement as follows;

The definition of displacement is an object's change in position, given by the difference between its start and finish locations

According to the definition of displacement, therefore, the magnitude of

the teachers displacement is the distance between the school and the

doctors office which is given by the difference between the coordinates of

the location of the school and the location of the doctors office

The magnitude of the displacement of the teacher = The coordinate of the location of the doctors office - The coordinate of the location of the school

Learn more about displacement here;

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Our Moon a. was a separate small planet before it was captured by the Earth's gravity. b. spun off the fast-spinning Earth during the early formation of the Solar System. c. coalesced from gas and dust in its current place next to the Earth. d. was formed by the collision of the Earth with a Mars-sized protoplanet.

Answers

Answer:

d. was formed by the collision of the Earth with a Mars-sized protoplanet.

According to the The giant-impact hypothesis the Moon was formed from the debris of a collision between the Earth and a Mars-sized protoplanet.

I need help asap please​

Answers

Answer:

I dont know answer Sorry For that thank u

Una grúa con un motor de 10 CV eleva 1000 kg de hierro hasta
una altura de 50 m del suelo en 2 minutos.
a) Expresa la potencia del motor en W.
b) ¿Qué trabajo realiza el motor?
c) Calcula el rendimiento del motor.

Answers

Answer:

can u write in eng I didn't recognize your language...

Name the types of motion represented by oA, AB and BC .​

Answers

Answer:

OA-Uniformly accelerated motion. AB-constant speed,hence uniform motion.BC-motion with uniform (-)ye acceleration.

1Dyne = How many Newtons??​

Answers

Answer:

answer to this question

1 × 10-5 newton

hope it helps:)

Answer:

I dyne= 1×10^-5 newtons

Explanation:

hope it will help you

The 11 th one please! Somebody help me:(

Answers

Answer:

203360Pa

Explanation:

Pressure= density of liquid*height*g

=1000*10*10

=100000Pa

Total pressure= water pressure + atmospheric pressure

=1000000+103360

=203360 Pascal

At what conditions acceleration of a body is zero?​

Answers

Answer:

when there is uniform velocity the acceleration of a body is zero

Velocity may be positive,negative or zero.Explain this statement with diagram.​

Answers

Answer:

/

Explanation:

Why is atmospheric pressure greater at low elevations and less at higher elevations?

Answers

Earth's gravity pulls air as close to the surface as possible. As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level.

4. What current is drawn by a 90 W light bulb on a 110 V household circuit?

Answers

Answer:

I = 0.82A

Explanation:

I = W/V

I = 90W/110V

I = 0.82A

Which property do the elements in each column of the representative elements series of the periodic table have in common?(1 point)

number of neutrons
number of orbitals
number of valence electrons
number of protons

Answers

The property that the elements in each column of the representative elements series of the periodic table have in common is: number of valence electrons.

An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.

Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.

Periodic table is an organized tabular array of all the chemical elements arranged in order of increasing atomic number (in rows).

Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.

In the periodic table, chemical elements that are having the same number of valence electrons are found in the same column.

This ultimately implies that, all the chemical elements such as Hydrogen, Sodium, etc., with one (1) valence electrons in their outermost shell (S-orbital) are found in the first (1st) column of the periodic table.

In conclusion, property that the chemical elements in each column of the representative elements series of the periodic table have in common is number of valence electrons.

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the force of attraction between the earth and objects on it is called..

Answers

Answer: gravitational pull? gravity

Explanation:

During what intervals was Jenny positively accelerating?

Answers

Answer:

3:00 - 3:02 and 3:07 - 3:08

Explanation:

Those are the only intervals in which Jenny's speed increased.

Answer and Explanation:

To know where Jenny was positively accelerating, we have to find where the slopes on the graph are increasing (in the positive direction).

By looking at the graph, we can see that at the intervals:

3:00 to 3:02 and 3:07 to 3:08

Jenny was positively accelerating, as there is an increase in speed during these time intervals.

#teamtrees #PAW (Plant And Water)

I hope this helps!

Do cheese and chips good?

Answers

They good good smack, nachos, cheesy chips, chips and quest, cheese and chips ( ˘ω˘ )
Please mark brainliest my good cheesy sire

why dont we put (-ve) sign when calculating charge in electrostatics ?​

Answers

Answer:

The negative sign represents the flow of charge in an opposite direction relative to point of action.

Write down the role played by four digestive juices in digestion and the
organs which secrete them.

Answers

Answer:

Explanation:Digestive juices secreted by various organs such as salivary glands in the mouth, stomach, liver and pancreas help in the process of digestion of food. Saliva secreted by the salivary glands in the mouth aids in the breakdown of starch present in the food to simple sugar


If Bulb B burns
out, what happens?
A Bulb A and C will stay lit.

Answers

Answer: C

Explanation:

Since bulb B is burnt out, the wires can't transfer to bulb A, so that's why bulb A will burn out.

If I get it wrong, sorry. Im still learning.

Find out the name of metals which can be obtained from the following .a) argentite b)hematite c)chalcopryite d)bauxite e)calverite​

Answers

Answer:

a). Silver, Ag

b). Iron, Fe

c). Copper, Cu

d). Aluminium, Al

e). Gold, Au

chuyển động thẳng đều là gì

Answers

Question:

What is uniform rectilinear motion?

Answer:

Uniform rectilinear motion is when an object travels at a constant speed with zero acceleration.

Which is the formula that describes the magnitude of an object's kinetic energy? A. kinetic energy = mass * (velocity)2 x 0.5
B. kinetic energy = mass x acceleration C. kinetic energy = mass x change in velocity
D. kinetic energy = mass x velocity​

Answers

Answer:

A

kinetic energy=(mv²)/2

(1/2)(mv²)

(mv²)*0.5

where m=mass and v=velocity/speed

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