The graph represents the path of an object thrown with a horizontal velocity from a certain height. what is the form of the graph?
a. a parabola with the vertex at (0,0) and a negative value for a
b. a parabola with the vertex at (0,0) and a positive value for a
c. an inverse graph
d. a linear graph

A. a parabola with the vertex at (0,0) and a negative value for a

Explanation:

The path of an object thrown with a horizontal velocity from a certain heigth is the path of a projectile, and it is a parabolic path. It is the resultant of two independent motions:

- a horizontal uniform motion, with constant horizontal velocity

- a vertical accelerated motion, with constant acceleration (equal to the gravitational aceleration) towards the ground

Due to the fact that conventionally the positive direction of the vertical axis is taken as upward, the acceleration of the vertical motion is directed downward, so toward negative direction, so the value of a (acceleration) is negative.

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