Astudent is playing with a radio-controlled race car on the balcony of a sixth-floor apartment. an accidental
turn sends the car through the railing and over the edge of the balcony. does the time it takes the car to fall
depend upon the speed it had when it left the balcony? assume the car is moving horizontally as it goes over
the edge of the balcony.

No, it is independent

Explanation:

As we know that car is moving horizontally

so the vertical component of the speed is zero initially

so in order to hit the ground we know that

so here we know that

on solving above equation for time

so we will say that it will not depends on the initial horizontal speed

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