Engineers are using computer models to study train collisions to design safer train cars. They start by modeling an elastic collision between two train cars traveling toward each other. Car 1 is traveling south at 18 m/s and has a full load, giving it a total mass of 14,650 kg. Car 2 is traveling north at 11 m/s and has a mass of 3,825 kg. After the collision, car 1 has a final velocity of 6 m/s south. What is the final velocity of car 2?

The “death throes” of stars are amongst the most complex phenomena in all of astronomy, and the “corpses” of stars amongst the most energetic and exotic objects in existence. beginning at the end of the core helium fusion stage in a star’s life, describe in detail the post-main sequence development of both (a) a 1.0 solar mass star, and (b) a 25.0 solar mass star. in what significant ways do they differ? what role does each of these types of stars play in the "star-gas-star" cycle and the evolution of chemical elements in our galaxy?

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?