6. a) The distance between the oxygen molecule and each of the hydrogen atoms in a water (H2O) molecule is 0.96 Å and the angle between the two oxygen-hydrogen bonds is 105°. Treating the atoms as particles, find the centre of mass of the system.
b) A stationary ball, with a mass of 0.2 kg, is struck by an identical ball moving at .4ms −1 After the collision, the second ball moves 60° to the left of its original direction. The stationary ball moves 30° to the right of the moving ball’s original direction. What is the velocity of each ball after the collision?