The mass density of a spherical galaxy varies as Kr over a large distance ‘r’ from its centre. In that region, a small star is in a circular orbit of radius R. Then the period of revolution, T depends on R as
see full answer
Your Exam Success, Personally Taken Care Of
1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya
a
T∝R
b
T2∝1R3
c
T2∝R3
d
T2∝R
answer is D.
(Unlock A.I Detailed Solution for FREE)
Best Courses for You
JEE
NEET
Foundation JEE
Foundation NEET
CBSE
Detailed Solution
Gravitational force on star FG=GmMr2 , where M is mass of galaxy within radius rSo, M= 0r4πr2drKr=4π2kr22⇒FG=mω2r⇒FG=m.r4π2T2⇒T2=4π2mrFG=4π2mrGmM/r2=4π2r3G4π2kr22⇒T2 ∝ r
The mass density of a spherical galaxy varies as Kr over a large distance ‘r’ from its centre. In that region, a small star is in a circular orbit of radius R. Then the period of revolution, T depends on R as