1Find the speed of a satellite in a circular orbit around th

1-Find the speed of a satellite in a circular orbit around the earth with a radius 2.93 times the mean radius of the earth; Radius of earth= 6.37·10³km; Mass of earth= 5.98·10²⁴ kg. (in m/s)

2- A star of mass 1.71×10³¹ kg and diameter 8.90E+9 m rotates with a period of 27.0 days. Suddenly the star changes size, and rotates with a new period of 16.0 days. Assuming a uniform density both before and after the size change, what is the new diameter of the star?

DATA:

Solution

G M m / r² = m v² / r

v² = G M / r

v = sqrt [G M / r ]

= sqrt [6.67 * 10^-11 * 5.98 *10²⁴) / (2.93 * 6.37 * 10⁶)]

= 4622 m/s