एक समान गोलाकार कोश (spherical shell) के अंदर रखे बिंदु द्रव्यमान पर कोश द्वारा लगाया गया कुल गुरुत्वाकर्षण बल कितना होता है?

On Earth, g ≈ 9.8 m/s2. If an object is moved to a location where g = 0, its mass:

The force with which the Earth attracts an object is called:

Two stars of masses m and 2m at a distance d rotate about their common centre of mass in free space. Their period of revolution is: