Two identical freight cars roll without friction towards each other on a level track. one car rolls 2 m/s the other 1 m/s. after the cars collide they couple and roll together with a speed of

Most short-period comets do not have randomly oriented orbits because

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?

What property of an object determines its inertia?