Physics!

The two stars in a certain binary star system move in circular orbits. The first star, Alpha, has an orbital speed of 36 km/s. The second star, Beta, has an orbital speed of 12 km/s. The orbital period is 137 d.
a) What is the mass of the star alpha?

b) What is the mass of the star beta?

c) One of the best candidates for a black hole is found in the binary system called A0620-0090. The two objects in the binary system are an orange star, V616 Monocerotis, and a compact object believed to be a black hole. The orbital period of A0620-0090 is 7.75 hours, the mass of V616 Monocerotis is estimated to be 0.67 times the mass of the sun, and the mass of the black hole is estimated to be 3.8 times the mass of the sun. Assuming that the orbits are circular, find the radius of the orbit of the orange star.

d) Find the radius of the orbit of the black hole.

e)Find the orbital speed of the orange star.

f)Find the orbital speed of the black hole.

  1. 👍 0
  2. 👎 0
  3. 👁 1,691
  1. These are Kepler's third law problems. Please show your work for further assistance.

    Or harvest your answers somewhere else

    1. 👍 1
    2. 👎 3
  2. I know I have to find angular speed in order to find the radius of orbit.

    With the radius of orbit and velocity I can find centripetal acceleration. I then apply Newton's 2nd Law to solve for the mass.

    I am stuck on finding angular speed...

    1. 👍 0
    2. 👎 0
  3. Hey there Aliison,
    For this problem, you don't actually need to use kepler's laws, all you have to do is 1) find both the radii of the of the stars to the center of the system (denoted by R_a and R_b using the period equation T=(2*pi*R)/v) then, since they are in stable orbits, you can relate the centripetal force (mV^2/R note that the radius here is either R_a or R_b) with he gravitational force between the two (G(m_a*m_b)/R^2 -- the R here is R_a+R_b) Hope this helps

    1. 👍 0
    2. 👎 0
  4. m_a = 7.80 x 10^29

    not sure about m_b

    1. 👍 1
    2. 👎 1
  5. m_b is 2.34*10^30
    radius of the orbit of the black hole
    R = 3.40×108 m
    orbital speed of the orange star
    440 km/s
    orbital speed of the black hole
    77.0 km/s

    1. 👍 2
    2. 👎 2
  6. ples show work

    1. 👍 1
    2. 👎 1

Respond to this Question

First Name

Your Response

Similar Questions

  1. physic

    Planet A and planet B are in circular orbits around a distant star. Planet A is 4.5 times farther from the star than is planet B. What is the ratio of their speeds vA/vB?

    asked by ozer on July 13, 2013
  2. SCIENCE HELP PLEEASE

    Given the following images, choose the one that most likely represents an O-class star. Star A is a yellow star. Star B is a blue star. Star C is a red star. Star D is a green star. A B C D is it b

    asked by Oscar on February 9, 2016
  3. physics

    Two stars in a binary system orbit around their center of mass. The centers of the two stars are 7.78x1011 m apart. The larger of the two stars has a mass of 4.19x1030 kg, and its center is 1.75x1011 m from the system's center of

    asked by Anonymous on March 27, 2014
  4. physics

    Distinguish between properties of the two major types of supernovae: massive star supernovae and white dwarfs. All supernovae represent the explosions of stars, but current understanding suggests there are two basic types of

    asked by Misty on April 29, 2011
  1. Physics

    A binary star system consists of two equal mass stars that revolve in circular orbits about their center of mass. The period of the motion, T=29.6 days, and the orbital speed v= 220 km/s of the stars can be measured from

    asked by Casey on July 12, 2011
  2. science help

    An astronomer sees two stars in the sky. Both stars are equally far from Earth, but the first star is brighter than the second star. Which of the following is a valid conclusion about the first star? It is larger than the second

    asked by Oscar on January 13, 2016
  3. science help PLS

    An astronomer see a star that is very far away but still very bright. What can she conclude about the star? The star must be very large. The star must be very small. The star must be moving away from Earth. The star must be moving

    asked by Oscar on February 4, 2016
  4. science help

    When nuclear fusion begins, what can be said about the internal processes within that star? Atoms in the star begin to split. Atoms in the star begin to combine. The star is turned into a nebula. The star is turned into a blue

    asked by Oscar on January 13, 2016
  1. physics

    In a certain binary star system, each star has the same mass as our sun, and they revolve about their center of mass. The distance between them is the same as the distance between the EArth and sun. Wha tis their period of

    asked by kristen on March 16, 2008
  2. Physics

    A star rotates in a circular orbit about the center of its galaxy. The radius of the orbit is 6.2 x 1020 m, and the angular speed of the star is 4.3 x 10-15 rad/s. How long (in years) does it take for the star to make one

    asked by Maggie on October 30, 2012
  3. physics 12

    a certain binary star system consists of two stars of masses m and 3m respectively separated by a distance of 1.5 x 10^12 m, measured between their centres. Theres stars revolve in sync with each other around their common centre

    asked by James on February 19, 2013
  4. Physics

    In a binary star system, two stars orbit about their common center of mass, as shown in the figure . If r2 = 2r1, what is the ratio of the masses m2/m1 of the two stars?

    asked by Real on July 30, 2011

You can view more similar questions or ask a new question.