Asmall car traveling with 5,000 kgm/s hits a light truck that was at rest at a red light. after the collision the small car bounces backwards with a momentum of 3,000 kgm/s. what would the momentum of the truck be after the collision?

8000

Explanation:

cause in the problem we dont have any ext Forces we know that the momentum of system is constant.

Fext=0

P1 + P2 = P1' + P2'

P2 = 0

5000 = -3000 + P2'

P2' = 5000+3000 = 8000

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