With science! (the first are part of the same question)

Which feature indicates that mars resides in the inner region of the solar system

Abumper car with a mass of 250 kg is traveling at a speed of 4 m/s. this bumper car collides and sticks to a second bumper car with a mass of 250 kg, which is initially at rest. what is the final speed of these two bumper cars after the collision, assuming they remain stuck together?

Which is an advantage of subdividing science into different areas?