1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
g100num [7]
3 years ago
5

In about 5 billion years, at the end of its lifetime, our sun will end up as a white dwarf, having about the same mass as it doe

s now, but reduced to about 15,000 km in diameter.What will be its density at that stage?
...?
Physics
1 answer:
vitfil [10]3 years ago
8 0
It is fine to use the equation given by Plitter, since we are told that the mass is about the same as it is now, and I seriously doubt the original question wants the student to go into relativistic effects, electron degeneracy pressure and magnetic effects that govern a real white dwarf star.
There is no need to make it unnecessarily complicated, when the question is set at high school level.  The question asks, given a particular radius, and a given mass, what will the density be (which in this case will be the average density).   To answer the question, one needs to know the mass of the sun (which is about 2×1030 Kg.  One needs to convert the diameter to a radius, and then calculate the spherical volume of the white dwarf.  Then one can use the formula given above, namely density=mass/volume
You might be interested in
A thin, light wire 75.2 cm long having a circular cross section 0.560 mm in diameter has a 25.2 kg weight attached to it, causin
blsea [12.9K]

Answer:

The stress is calculated as 1.003\times 10^{9}\ Pa

Solution:

As per the question:

Length of the wire, l = 75.2 cm = 0.752 m

Diameter of the circular cross-section, d = 0.560 mm = 0.560\times 10^{- 3}\ m

Mass of the weight attached, m = 25.2 kg

Elongation in the wire, \Delta l = 1.10\ mm = 1.10\times 10^{- 3}\ m

Now,

The stress in the wire is given by:

Stress,\ \sigma = \frac{Force,\ F}{Area,\ A}          (1)

Now,

Force is due to the weight of the attached weight:

F = mg = 25.2\times 9.8 = 246.96\ N

Cross  sectional Area, A = \pi (\frac{d}{2})^{2} = \pi (\frac{0.560\times 10^{- 3}}{2})^{2} = 2.46\times 10^{- 7}\ m^{2}

Using these values in eqn (1):

\sigma = \frac{246.96}{2.46\times 10^{- 7}} = 1.003\times 10^{9}\ Pa  

8 0
3 years ago
If you were creating a lamp by hand what type of material would you chose for the wiring and what material would you chose to co
anzhelika [568]
Copper because it contains alot of electricity
6 0
3 years ago
You stand on a straight desert road at night and observe a vehicle approaching. This vehicle is equipped with two small headligh
spayn [35]

To solve this problem we will apply the concepts related to Reyleigh's criteria. Here the resolution of the eye is defined as 1.22 times the wavelength over the diameter of the eye. Mathematically this is,

\theta = \frac{1.22 \lambda }{D}

Here,

D is diameter of the eye

D = \frac{1.22 (539nm)}{5.11 mm}

D= 1.287*10^{-4}m

The angle that relates the distance between the lights and the distance to the lamp is given by,

Sin\theta = \frac{d}{L}

For small angle, sin\theta = \theta

sin \theta = \frac{d}{L}

Here,

d = Distance between lights

L = Distance from eye to lamp

For small angle sin \theta = \theta

Therefore,

L = \frac{d}{sin\theta}

L = \frac{0.691m}{1.287*10^{-4}}

L = 5367m

Therefore the distance is 5.367km.

4 0
4 years ago
A particle, whose acceleration is constant, is moving in the negative x direction at a speed of 4.91 m/s, and 12.9 s later the p
Zinaida [17]

Answer:

The particle’s velocity is -16.9 m/s.

Explanation:

Given that,

Initial velocity of particle in negative x direction= 4.91 m/s

Time = 12.9 s

Final velocity of particle in positive x direction= 7.12 m/s

Before 12.4 sec,

Velocity of particle in negative x direction= 5.32 m/s

We need to calculate the acceleration

Using equation of motion

v = u+at

a=\dfrac{v-u}{t}

Where, v = final velocity

u = initial velocity

t = time

Put the value into the equation

a=\dfrac{7.12-(-4.91)}{12.9}

a=0.933\ m/s^2

We need to calculate the initial speed of the particle

Using equation of motion again

v=u+at

u=v-at

Put the value into the formula

u=-5.321-0.933\times12.4

u=-16.9\ m/s

Hence, The particle’s velocity is -16.9 m/s.

4 0
3 years ago
Is Li Chen abiotic or biotic?
kherson [118]

Answer:

abiotic

Explanation:

i think but dont take my word for it

8 0
3 years ago
Read 2 more answers
Other questions:
  • The chemical elements are arranged in order of increasing atomic number. The rows are called periods and the columns are called
    12·1 answer
  • What does an octopus have to do with why atoms bond with other atoms?
    8·1 answer
  • WHAT IS THE KE OF 2KG BALL AT SPEED 5M/S AT 40M TALL?
    14·1 answer
  • Two point charges of equal magnitude (and opposite sign) are 7.5 cm apart. At the midpoint of the line connecting them, their co
    9·1 answer
  • A particular gun (10kg) is able to fire 20 gram bullets at a speed of 350 m/s. From this information, calculate roughly how much
    15·1 answer
  • a plane passes over Point A with a velocity of 8,000 m/s north. Forty seconds later it passes over Point B with a velocity of 10
    8·1 answer
  • How do forces affect a body's motion?
    12·1 answer
  • Why do farmers need to use strategies like crop rotation?
    15·2 answers
  • 1, Can bed bugs adapt to the heat treatments? Why or why not?
    6·1 answer
  • For the galvanic cell at 298 k zn(s) 2in2 (aq)zn2 (aq) 2in (aq) eocell = 0.36 v what is the equilibrium constant, k?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!