How is gaia mapping used outside of astronomy-related endeavors

Acompound machine is also called a machine. a. force b. simple c. complex d. directional

Amoving freight car collides with an identical one that is at rest. if momentum is conserved, what happens to the second car after the collision? it attains the same speed as the first car. it moves at half the speed of the first car. it moves at twice the speed of the first car.

Iso need with this one really lost on it me on this