Two galaxies of masses 9 billion solar ,ass and 4 billion solar mass are 5 million light years apart. If, the sun has to cross the line joining them, without being attracted by either of them, through what piont it should pass?

Two particles of masses 2 kg and 3 kg are separated by 5 m. Then moment of inertia of the system about an axis passing through the centre of mass of the system and perpendicular to the line joining them is

Two particles of masses m_1 and m_2 are separated by a distance 'd'. Then moment of inertia of the system about an axis passing through centre of mass and perpendicular to the line joining them is

Three electrolytic cells A, B, C containing solution of ZnSO_4, AgNO_3 and CuSO_4 , respectively are connected in series. A. steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell B. How long did the current flow? What mass of copper and of zinc were deposited ?