A double star,with two star masses m1 & m2.They are rotating with constant angular speed. If max. distance of separation between them is R,find the angular speed of star in terms of m1,m2 & R

2 years ago


Answers : (1)


Hi Shweta

The above ques will be done with the concept of reduced mass...

according to the concept of reduced mass when two bodies rotate about their common centre of mass such that a force of attraction acts between them and the dist.b/n the 2 bodies remains constant then their angular velocites are exactly same both in magnitude and direction .the results for angular velocity and time period that u obtain for single bodies can be obtained by using the reduced mass of  2 body system .To reduce the 2-body system to 1-body just consider 1 body of mass=m(reduced mass) and consider its rotation about a fixed point at a dist=dist between the 2 bodies.thus u get a simple circular motin whose radius is known and the centrifugal force is balanced by the force of attraction that was originally present between the bodies. 

we can consider the 2-star system to be as 1 star having a mass
(m1+m2) this will rotate in circular motion about a fixed pt. and having radius equal to the separation b/n the 2 bodies and the force remaining the same towards the centre as b4 which in this case is the gravitation force of interaction.

the equations will be

mw2R=Gm1m2/R2.   solving u get w=(1/R)(G(m1+m2)/R) ie 1/R*root(G(m1+m2)/R)


Hope it helps!

2 years ago

Post Your Answer

More Questions On IIT JEE Entrance Exam

Ask Experts

Have any Question? Ask Experts
Post Question
Answer ‘n’ Earn
Attractive Gift
To Win!!!
Click Here for details
can we get admission in iit through NATA exam
Amit Shekhar 3 months ago
how to get admission in iit for architecture ….….…................is there any paper for architecture like jee main paper 2 ….….….….please tell …....explain procedure..........
Architecture Aptitude Test (AAT) is a test carried specially for the students interested in pursuing Architecture in IITs.It’s a 3 hour test which you need to give apart from JEE(Main)...
Aziz Alam 5 months ago
that means firstly i have clear jee main paper 2 and then jee advance then AAT
milind 5 months ago
can iit advance marks be used to get into best NIT’s
No... It has clearly been mentioned in the brochure the criteria for NIT. through central counselling. So JEE mains would be considered and not advanced for admission to NIT’s...
Ravi one month ago
Aziz Alam one month ago
sir how to find dissociation in chemical eq? 2 if temperature does not change in a rection does it mean that there is no reaction
Dissociation in chemistry and biochemistry is a general process in which molecules (or ionic compounds such as salts, or complexes) separate or split into smaller particles such as atoms,...
Suraj Prasad 2 months ago
please tell me the books which are having chapter wise(previous year iit questions) for practice
Dear paresh generally all latest edition include last year JEE question. you can also purchase last 10 year sample IIT JEE paper.(easly available ) Please feel free to post as many doubts on...
Badiuddin askIITians.ismu Expert 5 years ago
Hi Paresh, there are many publications avilable in the market giving the previous years chapterwise questions with answers... most familiar books are: Arihant MTG
askiitian.expert- chandra sekhar 5 years ago
which books are better for cracking AIIMS exam?
Donot go through many books. Be selective in checking out a good book and work around it. Read one good book but throughly. NCERT Books are a must. NCERT Books Physics: CBSE PMT set of 3...
Sunil Kumar FP 26 days ago
View all Questions »