1.) If the original star rotated once in 34 days, find the angular speed of the

Question

1.) If the original star rotated once in 34 days, find the angular speed of the neutron star.

--------- ? in rad/s

Under some circumstances, a star can collapse into an extremely dense object made mostly of neutrons and called a neutron star. The density of a neutron star is roughly 10^14 times as great as that of ordinary solid matter. Suppose we represent the star as a uniform, solid, rigid sphere, both before and after the collapse. The star's initial radius was 9.010^5 km (comparable to our sun); its final radius is 17 km. 1.) If the original star rotated once in 34 days, find the angular speed of the neutron star. --------- ? in rad/s

Explanation / Answer

By the conservation of angular momentum, Li = Lf

Iii = Iff

I of a sphere is 2/5MR2

The 2/5M will cancel out of noth sides since it stays constant, so we are left with

Ri2i = Rf2f

initial is found from 34 days to rotate once 34 days is 2937600 sec

One rotation is 2 rad

i = 2/2937600 = 2.139 X 10-6 rad/s

So...

(9 X 105)2(2.139 X 10-6) = (17)2(f)

f = 5995 rad/s

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.