Each railway car has a mass of 12,000 kg. before the cars collide, the car on the left has a speed of 32 m/s. what is the magnitude of its momentum?

3,84,000 Kg-m/s

Explanation:

Momentum of a body is equal to the product of mass and its velocity

Momentum = Mass x velocity

             = 12,000 Kg x 32 m/s

             = 3,84,000 Kg-m/s

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me