Chapter 8, Problem 8.46P

If the Sun could suddenly collapse to a black hole, how would the period of Earth’s revolution about it differ from what it is now?

What is the Schwarzschild radius for the black hole at the center of our galaxy if it has the mass of 4 million solar masses?

If a planet with 1.5 times the mass of Earth was traveling in Earth’s orbit, what would its period be?

Two binary stars, masses 1020 kg and 2×103 kg respectively, rotate about their common centre of mass with an angular velocity @. Assuming that the only force on a star is the mutual gravitational force between them, calculate w. Assuming the distance between the stars is 106 km

The radius of gyration of a disc of mass 100 gm and radius 5 cm about an axis passing through its centre of gravity and perpendicular to the plane is-

Suppose a star the size of our Sun, but with mass 5.0 times as great, were rotating at a speed of 1.0 revolution every 10 days. If it were to undergo gravitational collapse to a neutron star of radius 14 km, losing three-quarters of its mass in the process, what would its rotation speed be? Assume also that the thrown- off mass carries off either. a) no angular momentum b) its proportional share three-quarters of the initial angular momentum

A uniform, spherical cloud of interstellar gas has mass 1.8×1030 kg and radius 1.2×1013 m, and is rotating with period 1.5×106 years. If the cloud collapses to form a star 7.4×108 m in radius, what will be the star's rotation period?

The radius of Earth is 6370 km, and its orbital speed about the Sun is 30 km/s. Suppose Earth moves past an observer at this speed. To the observer, by how much does Earth’s diameter contract along the direction of motion?

Two stars M1 and M2 of equal mass make up a binary star system. They move in a circular orbit that has its center at the midpoint of the line that separates them. If M1 = M2 = 8.20 sm (solar mass), and the orbital period of each star is 2.70 days, find their orbital speed. (The mass of the sun is 1.99 10^30 kg.) km/s.