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
kvasek [131]
3 years ago
11

The mass of a star can be determined by studying ___.

Physics
2 answers:
oksian1 [2.3K]3 years ago
7 0

Answer:

C. Binary star systems

Explanation:

Citrus2011 [14]3 years ago
4 0
Answer: C. Binary star systems

Let’s see your options:

a) The <em>color of the star</em>: the color is not used in calculating the mass of a star, because it has no relation to it. Think about a red supergiant and a red dwarf: they have the same color, but they are completely different stars, with respectively a big and a small mass.

b) <em>Kepler’s laws</em>: these laws can be applied in what is called the “approximation of 1 body”, which means that is assumed that one body has a much bigger mass than the other and can be considered at rest. This is the case of a star-planet system and the mass that can be calculated is that of the planet.

c)<em> Binary star systems</em>: these are the only cases in which is possible the direct measure of the mass of the stars. Binary systems are classified as follows:
- Visual binaries: each star can be resolved and the motion around the center of mass can be measured.
- Astrometric binaries: only one star is visible, but the presence of the companion can be inferred by the movement of the first star around the system’s center of mass.
- Eclipse binaries: the two stars are not resolved (separated), but the luminosity varies periodically when one star eclipses the other.
- Spectroscopic binaries: the two stars are not resolved, but their spectrum reveals that they are a binary system.
In all these cases we have a “two-body problem” that can be solved by changing system of reference: the motion of bodies 1 and 2 is equivalent to the motion of a body of mass equal to the system’s reduced mass \mu =  \frac{M_{1} \cdot M_{2}}{M_{1} + M_{2}} moving in the potential generated by the total mass (M1 + M2) considered at rest. Hence, we can determine the masses of the two stars. 
You might be interested in
A 27.0-m steel wire and a 48.0-m copper wire are attached end to end and stretched to a tension of 145 N. Both wires have a radi
algol13

Answer:

The time taken by the wave to travel  along the combination of two wires is 458 ms.

Explanation:

Given that,

Length of steel wire= 27.0 m

Length of copper wire = 48.0 m

Tension = 145 N

Radius of both wires = 0.450 mm

Density of steel wire \rho_{s}= 7.86\times10^{3}\ kg/m^{3}

Density of copper wire \rho_{c}=8.92\times10^{3}\ kg/m^3

We need to calculate the linear density of steel wire

Using formula of linear density

\mu_{s}=\rho_{s}A

\mu_{s}=\rho_{s}\times\pi r^2

Put the value into the formula

\mu_{s}=7.86\times10^{3}\times\pi\times(0.450\times10^{-3})^2

\mu_{s}=5.00\times10^{-3}\ kg/m

We need to calculate the linear density of copper wire

Using formula of linear density

\mu_{c}=\rho_{s}A

\mu_{c}=\rho_{s}\times\pi r^2

Put the value into the formula

\mu_{c}=8.92\times10^{3}\times\pi\times(0.450\times10^{-3})^2

\mu_{c}=5.67\times10^{-3}\ kg/m

We need to calculate the velocity of the wave along the steel wire

Using formula of velocity

v_{s}=\sqrt{\dfrac{T}{\mu_{s}}}

v_{s}=\sqrt{\dfrac{145}{5.00\times10^{-3}}}

v_{s}=170.3\ m/s

We need to calculate the velocity of the wave along the steel wire

Using formula of velocity

v_{c}=\sqrt{\dfrac{T}{\mu_{c}}}

v_{c}=\sqrt{\dfrac{145}{5.67\times10^{-3}}}

v_{c}=159.9\ m/s

We need to calculate the time taken by the wave to travel  along the combination of two wires

t=t_{s}+t_{c}

t=\dfrac{l_{s}}{v_{s}}+\dfrac{l_{c}}{v_{c}}

Put the value into the formula

t=\dfrac{27.0}{170.3}+\dfrac{48.0}{159.9}

t=0.458\ sec

t=458\ ms

Hence, The time taken by the wave to travel  along the combination of two wires is 458 ms.

4 0
3 years ago
Planet, , galaxy, universe. What is missing in the ordered sequence of the cosmos? A. Sun, B. Earth, C. Nebulae, D. Solar system
Artemon [7]
D; solar system, because the planets are inside it.
8 0
3 years ago
Read 2 more answers
A ceiling fan with 90-cm-diameter blades is turning at 64 rpm . Suppose the fan coasts to a stop 28 s after being turned off. Wh
mixas84 [53]

Answer:

the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.

Explanation:

Given;

diameter of the ceiling fan, d = 90 cm = 0.9 m

angular speed of the fan, ω = 64 rpm

time taken for the fan to stop, t = 28 s

The distance traveled by the ceiling fan when it comes to a stop is calculated as;

d = vt = \omega r\times  t= ( \frac{64 \ rev}{\min} \times \frac{2 \pi \ rad}{rev} \times \frac{1 \min}{60 \ s} \times 0.9 \ m) \times 28 \ s\\\\d = 168.89 \ m

The speed of the tip of a blade 10 s after the fan is turned off is calculated as;

v = \frac{d}{t} \\\\v = \frac{168.89}{10} \\\\v = 16.889 \ m/s

Therefore, the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.

4 0
3 years ago
What forces are those that act on an object causing the net force to be something other than zero?
Arisa [49]
Gravity is all ways pulling down and the normal force acting on top of the object and for it to have to push or pull to the object
3 0
3 years ago
On hot sunny days or days with thin clouds, the temperature over the land is warmer than the temperature over the water. The war
Luden [163]

Answer:

i think it would be a but i am not 100% sure on that

4 0
3 years ago
Other questions:
  • A 10.0-cm-diameter and a 20.0-cm-diameter charged ring are arranged concentrically (so they share the same axis). Assume both ar
    6·1 answer
  • A bicycle is heading west. It goes 500m in 5 minutes. What is its velocity?
    12·2 answers
  • Are any minerals flammable
    11·2 answers
  • how do you describe and determine the direction of the magnetic field produced by an electric current?
    14·1 answer
  • A spaceship accelerates from 0m/s to 40m/s in 5 seconds. What is the acceleration of the spaceship
    7·1 answer
  • The focal point of a concave mirror is _____ the mirror. ( in front of; behind)
    9·2 answers
  • Why would it be hard to find the ideal light intensity if the temperure were very hot or cold?
    7·1 answer
  • Whwhich pf the fallowing equations can be used to directly calculate an objects impulse
    10·2 answers
  • Kim holds a pinwheel in the air and says it can be used to model a source of energy. Identify the type of energy Kim's pinwheel
    14·1 answer
  • What can you do to prevent an echo and a reverberation in cinema halls and auditorium?<br>​
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!