A certain star has a temperature twice that of the Sun and a luminosity 70 times greater than the solar value. What is its radius, in solar units

Answers

Answer 1

Answer:

[tex] R = 2.1R_{\bigodot} [/tex]

                         

Explanation:                          

The radius (R) is related to temperature (T) and the luminosity (L) as follows:    

[tex] L = T^{4} \times R^{2} [/tex]      

By solving the above equation for R we have:

[tex] R = \frac{\sqrt{L}}{T^{2}} [/tex]

With [tex]L = 70L_{\bigodot}[/tex] and [tex]T = 2T_{\bigodot}[/tex] we have:

[tex] R = \frac{\sqrt{70L_{\bigodot}}}{(2T_{\bigodot})^{2}} [/tex]

[tex] R = \frac{\sqrt{70}}{(2)^{2}} [/tex]

[tex] R = 2.1R_{\bigodot} [/tex]

Therefore, the radius is 2.1 times that of the Sun.

I hope it helps you!


Related Questions

How long would it take a 500. W electric motor to do 15010 J of work?

Answers

time = energy / power = 15010 / 500 = .... seconds

Bicyclist travels at an average velocity of 11.2 km/h [W]. How far will the bicyclist travel in 175 minutes?

Answers

Answer:

32.67km

Explanation:

~= round off

11.2km/h~3.11m/s

175minutes=10500s

10500*3.11~32, 666.67m

=32.66667km

~ 32.67km

The first group of planets that are made of rock and closest to the sun

Answers

Answer:

A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun

what is a factor that scientists use to classify orders of soil?

Answers

climate, plant type, soil composition.

Which form of energy has the most potential globally

a) Solar energy

b) Bio energy

c) Wind energy

d) Geothermal energy

Answers

Answer:

i think the answer is solar,

Explanation:

because it is a natural resource im sorry if im wrong

b. Interpret Data Solution A has a pH of 1.6.
Solution B has a pH of 4. Which solution
has a greater concentration of hydrogen
ions? Explain.

Answers

Answer:

Solution A has a pH of 6 and solution B has a pH of 8. Which of the following is true regarding the concentration of hydrogen ions in each solution? A) A has 100 times greater H+ concentration than B. B) B has 100 times greater H+ concentration than A. C) A has 7/9 of the H+ concentration of B. D) A has 9/7 of the H+ concentration of B. E) none of these

Explanation:

Hey im super sorry if i get this wrong :)

pls answer this
quick as possible

Answers

Answer:

The answer is the 4th one

Explanation:

Good luck man

A horizontal force of 100 N is applied to move a 50-kg cart (initially at rest) across a 10 m level surface. What is the final kinetic energy of the cart?

Answers

The net force on the cart is 100 N in the direction of its motion, so by Newton's second law we can find the acceleration a applied to it:

100 N = (50 kg) a

a = (100 N) / (50 kg)

a = 2 m/s²

The cart starts at rest and travels a distance of 10 m, so that its final velocity v satisfies

v ² - 0² = 2 (2 m/s²) (10 m)

v ²= 40 m²/s²

and so the cart ends up with kinetic energy

KE = 1/2 m v ² = 1/2 (50 kg) (40 m²/s²) = 1000 J

Full moon is located______

a. farthest from the Sun

b. at a 90 degree angle with the Sun and Earth

c. closest to the Sun

Answers

Answer:

Im going to take an educated guess and say its B.

Explanation:

A Full moon is located farthest from the Sun. Thus, the correct option for this question is A.

What is a Full moon?

A full moon may be defined as one of the types of lunar phases when the Moon significantly appears fully illuminated from Earth's perspective. This event typically occurred when Earth is located between the Sun and the Moon.

When the earth is located between the sum and the moon, it is the time when the moon is located farthest from the sun. And it directs to an event of a full moon. The average time duration of the full moon and the repetition of the same phase normally requires 29.53 days.

Therefore, the Full moon is located farthest from the Sun. Thus, the correct option for this question is A.

To learn more about the Full moon, refer to the link:

https://brainly.com/question/15032553

#SPJ2

A batter hits a foul ball. The 0.140-kg baseball that was approaching him at 40.0 m/s leaves the bat at 30.0 m/s in a direction perpendicular to the line between the batter and the pitcher. What is the magnitude of the impulse delivered to the baseball?
A) 9.80 Ns
B) 3.50 Ns
C) 7.00 Ns
D) 5.60 Ns
E) 1.40 Ns

Answers

Answer:

The magnitude of the impulse delivered to the baseball is 7.0 Ns

Explanation:

Given;

mass of the foul ball, m = 0.14 kg

initial velocity, u = 40 m/s

final velocity, v = 30 m/s in perpendicular direction

Impulse is given as change in momentum;

initial momentum in horizontal direction, Pi = mu

Pi = 0.14 x 40 = 5.6 Ns

final momentum in perpendicular direction, Pf = mv

Pf = 0.14 x 30

Pf = 4.2 Ns

The resultant impulse is given by;

J² = 5.6² + 4.2²

J² = 49

J = √49

J = 7.0 Ns

Therefore, the magnitude of the impulse delivered to the baseball is 7.0 Ns

Rita wants to make some toast for breakfast, which she knows involves a chemical change to the bread.
She puts a slice of bread in the toaster, but, after 10 minutes, she notices that the sides of the bread are
black. What caused this chemical change to go too far?
A. an increase in temperature
B. a decrease in temperature
C. the size of the bread
D. the type of bread

Answers

Answer:

A

Explanation:

The toaster was too high so its the increase in eat

It will be easier to lift a load in wheel barrow if the load is moved
towards the wheel.why​

Answers

Answer:

the moment

Explanation:

the shorter the distance from the force, the lesser the torque acting on it

An artery with cross sectional area of 1 cm2 branches into 20 smaller arteries each with 0.5 cm2 cross sectional area. If the velocity of blood in the thicker artery is v, what is the velocity of the blood in the thinner arteries

Answers

Answer:

The velocity of the blood in the thinner arteries is 0.1 times that of the thicker artery.

Explanation:

To find the velocity of the blood we need to use the continuity equation:

[tex] n_{1}A_{1}v_{1} = n_{2}A_{2}v_{2} [/tex]   (1)  

Where:

n: is the number of branches

A: is the cross-sectional area

v: is the velocity

For artery 1, we have:

n₁ = 1, A₁ = 1 cm², v₁ = v

For the 20 arteries (2), we have:

n₂ = 20, A₂ = 0.5 cm², v₂ =?

By using equation (1):

[tex] n_{1}A_{1}v_{1} = n_{2}A_{2}v_{2} [/tex]

[tex] 1 cm^{2}*v = 20*0.5 cm^{2}*v_{2} [/tex]

[tex] v_{2} = \frac{1 cm^{2}*v}{20*0.5 cm^{2}} = \frac{v}{10} = 0.1v [/tex]

Therefore, the velocity of the blood in the thinner arteries is 0.1 times that of the thicker artery.

I hope it helps you!      

Please help with this physics question

Answers

The correct answer is A continúe moving with constant velocity

Sean, whose mass is 60 kg, is riding on a 5.0 kg sled initially traveling at 8.0 m/s. He brakes the sled with a constant force, bringing it to a stop in 4.0 s. What force does he apply?

Answers

Answer:

130N

Explanation:

according to Newtons second law;

F = ma

F = m(v-u)/t

m is the mass = 60+5 = 65kg

v is the final velocity = 0m/s

initial velocity = 8m/s

time t = 4.0s

F = 65(8)/4

F = 65*2

F = 130N

Hence he applied a force of 130N

Two masses are to collide directly with each other. One has a mass of 5 kg and a velocity of 2 m/s. The other has a mass of 3 kg and a velocity of 1 m/2. The collision is perfectly inelastic. Find the velocity of the masses after the collision.

Answers

Answer:

v₃ = 1.625 [m/s]

Explanation:

To solve this problem we must use the definition of linear momentum conservation, which tells us that momentum is conserved before and after a collision.

Since the collision is inelastic, the two bodies are joined after the collision.

P = m*v [kg*m/s]

m = mass [kg]

v = velocity [m/s]

where:

P = lineal momentum [kg*m/s]

Now, it is important to clarify that in the following equation we will take the left side of the equation as the momentum before the collision and the right side of the equal sign as the momentum after the collision.

Pbefore = Pafter

(m₁*v₁) + (m₂*v₂) = (m₁+m₂)*v₃

where:

m₁ = mass one = 5 [kg]

v₁ = velocity of the mass one = 2 [m/s]

m₂ = mass two = 3 [kg]

v₂ = velocity of the mass two = 1 [m/s]

v₃ = velocity of the combined masses after the collision [m/s]

Now replacing we have:

(5*2) + (3*1) = (5 + 3)*v₃

10 + 3 = 8*v₃

v₃ = 13/8

v₃ = 1.625 [m/s]

A car drives 150 km SE and then 50 km due N. What is the car's displacement?

Answers

Answer:

If the car travels 150 kilometers to the Southeast, and then 50 kilometers to the North, it is understood that the car does not travel the same way out as it does back. Therefore, the car's displacement will be the sum of both distances traveled, that is, 150 + 50, which is equal to 200. Therefore, the car traveled about 200 kilometers from its starting point.

how can voltage be produced by magnetism and motion?​

Answers

Answer:

Electromagnetic Induction by a Moving Magnet

Then the action of moving a coil or loop of wire through a magnetic field induces a voltage in the coil with the magnitude of this induced voltage being proportional to the speed or velocity of the movement.

Explanation:

Moderate injuries are generally __________.
A.
life-threatening
B.
soft tissue injuries
C.
bumps and bruises
D.
too serious for first aid


Please select the best answer from the choices provided.

A
B
C
D

Answers

Answer:

B. soft tissue injuries

Explanation:

i took the test on edge and its really the only one that would make sense if you payed attention to the lesson  :)

A biker first accelerates from 0.0 m/s to 6.0 m/s in 6 s, then continues at this speed for 5 s. What is the total distance traveled by the biker?

100 m

80 m

30 m

48 m

PLZ heeeeelp ​

Answers

Answer:

48m

Explanation:

Given the following data;

Initial velocity = 0m/s

Final velocity = 6m/s

Time, t = 6 secs

Time, T2 = 5 secs

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

Substituting into the equation;

[tex]a = \frac{6 - 0}{6}[/tex]

[tex]a = \frac{6}{6}[/tex]

Acceleration, a = 1m/s²

To find the distance covered in the first phase;

Solving for distance, we would use the second equation of motion;

[tex] S = ut + \frac {1}{2}at^{2}[/tex]

Substituting the values into the equation;

[tex] S = 0(6) + \frac {1}{2}*1*(6)^{2}[/tex]

[tex] S = 0 + \frac {1}{2}*1*36[/tex]

[tex] S = 0.5 *36[/tex]

Distance, S1 = 18m

For the second phase, time T2 = 5 secs;

Mathematically, speed is given by the equation;

[tex]Speed = \frac{distance}{time}[/tex]

Making distance the subject of formula, we have;

[tex]Distance, S = speed * time[/tex]

Substituting into the above equation;

[tex]Distance, S = 6 * 5[/tex]

Distance, S2 = 30m

Total distance = S1 + S2 = 18m + 30m = 48m

Total distance = 48m

Therefore, the total distance traveled by the biker is 48m.

HELP ASAP!!!!!!!!!
Mark and Steven were conducting an investigation where they were measuring the energy of a glass marble as it rolled down a ramp. According to their calculations, the total energy of the marble decreased. Which statement below is the best explanation for the decrease in total energy?
A) It decreased because it was destroyed by the interaction with the ramp
B) The total energy always decreases in an energy conversion
C) They were incorrect; the energy totals should have been the same
D) The energy decreased because heat resulted from friction between the marble and the ramp

Answers

B) The total energy always decreases in an energy conversion,

This is because: Energy decreases as it moves up trophic levels because energy is lost as metabolic heat when the organisms from one trophic level are consumed by organisms from the next level. Trophic level transfer efficiency (TLTE) measures the amount of energy that is transferred between trophic levels

Hope this helps! ✨

If you cannot exert enough force to loosen a bolt with a wrench, which of the following should you do?

Question 5 options:

1.) Tie a rope to the end of the wrench and pull on the rope.
2.) Use a wrench with a longer handle.
3.) You should exert a force on the wrench closer to the bolt.
4.) Use a wrench with a shorter handle.

Answers

Answer:

2.) Use a wrench with a longer handle.

Explanation:

It is suggested to use a wrench with longer handle if you cannot exert enough force to loosen a bolt with a wrench.

In doing this work, the torque which is the force that can turn the screw is not enough;

      Torque  = force x distance

If we increase the distance or the length of the handle, we can generate more torque to overcome the force needed.

Find an expression for the center of mass of a solid hemisphere, given as the distance R from the center of the flat part of the hemisphere. Express your answer in terms of R. Express the coefficients using three significant figures.

Answers

Answer:

z_c = ⅜R

Explanation:

If we assume that the hemisphere has uniform density, we can express the centre of mass as;

z_c = (ρ/M)∫∫∫ z•dV

We know that density(ρ) = mass(M)/volume(V)

Thus, Vρ = M

And volume of hemisphere = 2πr³/3

Thus;

2Vρπr³/3 = M

So;

z_c = (ρ/(2Vρπr³/3))∫∫∫ z•dV

Where r = R in this case.

ρ will cancel out to give;

z_c = (3/(2πr³))∫∫∫_V (z•dV)

In spherical coordinates,

r is radius

Φ = angle between the point and the z − axis

θ = azimuthal angle

Therefore, the integral becomes what it is in the attached image.

I've completed the explanation as well in the attachment.

If the jet is moving at a speed of 1140 km/h at the lowest point of the loop, determine the minimum radius of the circle so that the centripetal acceleration at the lowest point does not exceed 6.0 g's.

Answers

Answer:

The radius is  [tex]r =1705.44 \ m[/tex]

Explanation:

From the question we are told that

   The speed is [tex]v = 1140 \ km /h = \frac{1140 * 1000}{3600} = 316.67 \ m/s[/tex]

   The centripetal acceleration is  [tex]a = 6 g's = 6 * 9.8 = 58.8 \ m/s^2[/tex]

Generally the centripetal force acting on the jet is mathematically represented as  

        [tex]F_c = \frac{m * v^2 }{r}[/tex]

Generally this centripetal force is equal to the net force acting which according to Newton's third law is mathematically  represented as

      [tex]F = m * a[/tex]

So

      [tex]\frac{m * v^2 }{r} = ma[/tex]

=>   [tex]\frac{ v^2 }{r} = a[/tex]

=>  [tex]r = \frac{v^2}{a}[/tex]

=>  [tex]r = \frac{316.67^2}{58.8}[/tex]

=>  [tex]r =1705.44 \ m[/tex]

things that affects the demand for electricity

Answers

New inventions like :
Solar panel
Wind mill
And etc .

How many bonds can antimony form?

Answers

Answer:

An antimony can form 3 bonds

Let me know if this helps

Thanks!

:)

Explanation:

A box with weight of magnitude F_G = 2.00 N is lowered by a rope down a smooth plane that is inclined at an angle φ = 30.0 degrees about ve the horizontal. The normal force acting on the box has a magnitude n = 1.73 N, the tension force is 1.00 N, and the displacement Δr of the box is 1.80 m down the cloned plane.

What is the work W_G done on the box by the gravity?

Answers

Answer:

1.8 J

Explanation:

I had this exact question today and found someone who had solved it before, this was their response to the work done by gravity. They used the name "physicsmom"

Vertical distance = 1.8 sin 30 = .9 m

W = 2 N * .9 m = 1.8J

Good luck! I hope this helps!

The work done on the box by the gravity is 0.072 J.

The given parameters;

weight of the box, [tex]F_g[/tex] = 2 Ninclination of the rope, φ = 30⁰normal force acting on the box, n = 1.73 Ntension on the rope, T = 1 Ndisplacement of the box, Δr = 1.8 m

The work done on the box by gravity is calculated as follows;

W = FΔr

where;

F is the net horizontal force on the block

The net horizontal force on the box  is calculated as follows;

[tex]\Sigma F_x = F_g sin(\theta ) - F_k\\\\ \Sigma F_x = F_g sin(\theta ) - \mu_k F_n \\\\ \Sigma F_x = 2 \times sin(30 ) - (tan \theta) \times F_n\\\\ \Sigma F_x = 1 - (tan\ 30) \times 1.73\\\\ \Sigma F_x = 0.04 \ N[/tex]

The work done on the box by gravity is calculated as;

W = 0.04 x 1.8

W = 0.072 J.

Thus, the work done on the box by the gravity is 0.072 J.

Learn more here: https://brainly.com/question/14945453

An electron (restricted to one dimension) is trapped between two rigid walls 1.40 nm apart. The electron's energy is approximately 19 eV. (a) What is the quantum number n for the energy state that the electron occupies? (b) Based on the quantum number you found in part (a), calculate a more precise value for the electron's energy in eV), expressed to at least three significant figures. (Use any physical constants or unit conversions to at least four significant figures in your calculations.) _________ eV

Answers

Answer:

a)    n = 9.9       b)      E₁₀ = 19.25 eV

Explanation:

Solving the Scrodinger equation for the electronegative box we get

         Eₙ = (h² / 8m L²2) n²

where l is the distance L = 1.40 nm = 1.40 10⁻⁹ m and n the quantum number

 In this case En = 19 eV let us reduce to the SI system

          En = 19 eV (1.6 10⁻¹⁹ J / 1 eV) = 30.4 10⁻¹⁹ J

          n = √ (In 8 m L² / h²)

let's calculate

          n = √ (8  9.1 10⁻³¹ (1.4 10⁻⁹)²  30.4 10⁻¹⁹ / (6.63 10⁻³⁴)²

          n = √ (98)            n = 9.9

since n must be an integer, we approximate them to 10

b) We substitute for the calculation of energy

        In = (h² / 8mL2² n²

        In = (6.63 10⁻³⁴) 2 / (8 9.1 10⁻³¹  (1.4 10⁻⁹)² 10²

        E₁₀ = 3.08 10⁻¹⁸ J

we reduce eV

      E₁₀ = 3.08 10⁻¹⁸ j (1ev / 1.6 10⁻¹⁹J)

      E₁₀ = 1.925 101 eV

      E₁₀ = 19.25 eV

the result with significant figures is

        E₁₀ = 19.25 eV

What is the momentum of 100 kg running at 4m/s north?

Answers

The momentum is known as mass x velocity then u should say that it will be 400 kg m/s

Can someone please help me with this problem. I’ve tried but I can’t seem to figure it out.

Answers

The last one, Tension = 30N, Normal force = 20 N
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