Atrain consists of a caboose (mass = 1000 kg), a car (mass 2000 kg), and an engine car (mass 2000 kg). if the train has an acceleration of 5 m/s2, then the tension force in the coupling between the middle car and the engine car is

25,000 n
20,000 n
15,000 n
10,000 n

some think that theories become laws, but theories and laws have separate and distinct roles in the scientific method. a law is a description of an observed phenomenon in the natural world that hold true every time it is tested. it doesn't explain why something is true; it just states that it is true.

with the invention of the automobile, the woman of the house could drive to the store and get groceries. women were also free to socialize more. during world war ii women were allowed to work in factories to the war effort and could drive to work or ride mass transit buses to their jobs.