When a star collapses it significantly shrinks in size and spins up. Consider a star with...

 

Transcribed Image Text:

When a star collapses it significantly shrinks in size and spins up. Consider a star with a mass of M = 2.2x1030 kg and an initial radius of R₁ = 7.1x105 km. If the initial period of rotation of the star is T₁ = 29.3 days, find the new rotational period after it collapses to a final radius of Rf = 7.1x10³ km. Treat the star before and after the collapse as a solid sphere with uniform mass distribution (which is not true, of course, but good enough for an estimation). Find the ratio between the final and initial rotational kinetic energies of the star. The increase in the rotational kinetic energy of the star comes from gravity. How much work is done by the gravity force while collapsing the star? When a star collapses it significantly shrinks in size and spins up. Consider a star with a mass of M = 2.2x1030 kg and an initial radius of R₁ = 7.1x105 km. If the initial period of rotation of the star is T₁ = 29.3 days, find the new rotational period after it collapses to a final radius of Rf = 7.1x10³ km. Treat the star before and after the collapse as a solid sphere with uniform mass distribution (which is not true, of course, but good enough for an estimation). Find the ratio between the final and initial rotational kinetic energies of the star. The increase in the rotational kinetic energy of the star comes from gravity. How much work is done by the gravity force while collapsing the star?

Answer rating: 100% (QA)

Solution To find the new rotational period of the star we can use the conservation of angular momentum which states that the product of the moment of ... View the full answer