A helium atom (m = 6.6465 x 10-27 kg) moving at a speed of VHe = 1.518 106 m/s collides with an atom of nitro- gen (m = = 2.3253 10-26 kg) at rest. After the collision, the helium atom is found to be moving with a velocity of He 1.199 x 106 m/s at an angle of 0e = 78.75 rela- tive to the direction of the original motion of the helium atom. (a) Find the velocity (magnitude and direction) of the nitrogen atom after the collision. (b) Compare the kinetic energy before the collision with the total kinetic energy of the atoms after the collision.