Using the latest information from the recent MESSENGER mission to Mercury and the Lunar Reconaisance Orbiter (LRO) to the moon and discuss how finding water ice has affected our perception of these two celestial objects.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.