Question

Question 16 10 pts A sun-like star with mass M = 2.00 x 1030 kg and radius R = 7.0 x 105 km rotating once per month collapses into a neutron star (r = 16 km). What is the rotational speed of the sun-like star in rev/s? (1 month = 30 days, 1 year = 365 days, and 1 day = 86400 s.) O 2.74 x 10 ºrev/s O 3.86 x 107 rev/s O 1.0 rev/s O 1.16 x 10 Srev/s 30.0 rev/s 0.03 rev/s

The other 3 questions continue with question 16

Answer 1

8 16 m y - 16 X10 M = 2x1030 kg ; R = 7x10 16x103 m I rev /month speed rev/day (given). Rotational - 30 rew /bour . 30x24 rev/min 11 30 x 24. *60 reu uls = 30x24 X 60 X 60 -7 3.86 X10 reu ls (Ans) Moment of inertia of solidl sphere, २ 5 Isa me 2 x 2x10 30 x (7x108)" 3. 92x1047 kgm² cans) = CS Scanned with CamScanner

18 mass افر When the stau collapses is to beutron star, remains same but radius elecreeises. Initial moment of Inertia, I = 2 MRP Initial speed, = 3.86 x 107 kgm. Final moment of inertia , I2 = 2 Mge final speed, W2 According to law of conscnation of anguleu momentum, Li=LQ I w, zlauer 9 > a Mge ca معلا = EM R²xco, R²w, R²w, ² ula 2 was 2 7 х (7x103) 3.86 X10 2 (16x103 = 738.83 rev/s Cans) = 738 rev's CS Scanned with CamScanner

o period of rotational motion of neutron steel Не fоrсими и Аглаоси Т. (н rotationed speed a (1) 738 = 1.4 x 1p-3s CAus) = 1, 4 mS CS Scanned with CamScanner