How are the ideas of democritus and dalton similar? how are they different?

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.

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius

If anyone who can me with this hw? i would really appreciate it