A log is dragged on a horizontal slab of concrete with a weight of 980 N . if the applied horizontal force is 735 N , calculate the kinetic friction between the two surfaces​

What happens to light waves from a star as the star moves away from earth?

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.

As the distance from a magnet increases, what happens to the magnet force?