Starting from rest, a car accelerates at a rate of 10.7 m/s^2 for 12 seconds. what is its velocity at the end of this time?

Velocity of the car at the end of this time=128.4 m/s

Explanation:

initial velocity Vi=0

final velocity=V

acceleration= a=10.7 m/s²

time =t=12 s

using kinematic equation V= Vi + at

V=0+ 10.7 (12)

V=128.4 m/s

Thus the final velocity of the car =128.4 m/s

u=13

v=30

s/t=u+1\2at

=13+431/2

=13+265.5

=278.5

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