How did the city-state of athens make laws

What acceleration is produced when a 3,000-n force acts on a 1,200-kg car? ignore the friction

Given: circle a externally tangent to circle b. how many possible common tangents to circles a and b can exist? 2 3 4

Ascientist is explaining how background cosmic radiation gives evidence of the big bang theory. she says that radiation has been detected everywhere equally as heat in the universe and is increasing. this has been shown to be residual radiation from the big bang. what error did the scientist make?