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
sir, Can you please tell me how to apply for tensors 2014,
Hello Student, Go to the website tensor.in and follow the instructions. We at askiitians also have a full fledge testseries providibg you a set of full styllabus test for both jee mains and...
Nishant Vora 4 months ago
Visit our website to buy all india test-series provided by askiitians:- http://www.askiitians.com/packages/PackageDetail.aspx?packageID=17 Thanks
Nishant Vora 4 months ago
sir how can i attend the full test series of ask iitians
AJAY PILLAI K 4 months ago
is 10 matks required for iit jee exams or jee mains?
Year of passing of class 12 th makes the difference not 10 th . You have two chances, the year you appear for 12 th and year later....
Aziz Alam 3 months ago
Aziz Alam 3 months ago
sir i have appered for my 10 in 2013 but fue to some reasons i discontinued this year and now im gona write my iit exam in 2016 will it make any difference
vignesh 3 months ago
sir, pl. help me to solve following problems of permutation & combination- Q1. how many divisors of 9000 are even but not divisible by 4?also find the sum of such nos. Q2. the no. of ways an...
[Q-1]9000=3 2 5 3 2 3 we have to take exactly one 2. so number of ways (2+1)(3+1)(1)= 12 Sum of such numbers =(2)(3 0 + 3 1 +3 2 )(5 0 +5 1 +5 2 +5 3 ) [Q-2] first of all give 2 marks to...
Nishant Vora 4 months ago
is modern abc guide useful to crack jee
modern abc is a good book but not sufficient enough to crack jee as it does not have more questions in some topics
anshul matani 5 days ago
which is better iit roorkee cse or iit kanpur mechanical
Both are good choose the one that interests u
needhelp 6 months ago
what is state management in web application?why it is required ? give me list of state managemenet objects?
View state, control state, hidden fields, cookies, and query strings all involve storing data on the client in various ways. However, application state, session state, and profile properties...
Kevin Nash 5 years ago
A new instance of the Web page class is created each time the page is posted to the server. In traditional Web programming, this would typically mean that all information associated with the...
Jitender Pal 5 years ago
View all Questions »