Using the chart, determine the amount of Co-57 present on January 21 if you had a sample of 8g on January 1st. A) 2 g B) 4 g C) 16 g D) 25 g

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.