0
$\begingroup$

At the COM of a binary star system (where both stars has a different mass), the net force at the centre of mass is non-zero.

Does this mean that the COM will be accelerating? And if so, wouldn't the velocity of the binary star system keep on increasing?

However, it doesn't make sense if the velocity keeps increasing. So what is the error here?

Improve this question
$\endgroup$
2
  • $\begingroup$ "At the COM of a binary star system (where both stars has a different mass), the net force at the centre of mass is non-zero." What makes you think this? $\endgroup$
    – RC_23
    Commented Oct 9, 2022 at 2:03
  • $\begingroup$ We can have an external potential that accelerates the center of mass of a binary star system. Indeed, every binary star system in a galaxy has an accelerating center of mass because the system orbits around the center of the galaxy. If that potential is zero, however, then the center of mass will not accelerate. $\endgroup$
    – FlatterMann
    Commented Oct 9, 2022 at 2:48

1 Answer 1

Reset to default
2
$\begingroup$

It is not entirely clear what you mean by "the net force at the centre of mass," since forces act on objects, and there need not be an object at the centre of mass. Presumably, you mean to say that the gravitational field is non-zero at the centre of mass; i.e. if there were on object at the centre of mass, the net force on it would be non-zero. This does not mean that the centre of mass will accelerate, but rather that an object at the centre of mass will accelerate.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.