An air track car with a mass of 0.55 kg and velocity of 5.8 m/s to the right collides and couples with a 0.45 kg car moving to the left with a velocity of 3.9 m/s. What is the combined velocity of the cars just after the collision?

Explanation:

Given:

m1 = 0.55 kg

m2 = 0.45 kg

vi1 = +5.8 m/a

vi2 = -3.9 m/a

Solve for V

m1vi1 + m2vi2 = (m1 + m2)V

(0.55 kg)(+5.8 m/s) + (0.45 kg)(-3.9 m/s) = (0.55 + 0.45)V

V = +1.46 m/a

This means that the combined mass after the collision is moving to the right at 1.46 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