can anyone give a thorough explantation of why the acceleration in the x direction is 0 and y direction is 9.8

Answer 1

I assume your are talking about a constant velocity object, like a baseball, thrown across a field.

In physics, going across is considered in the x direction and up/down is the y direction.

You throw a baseball straight out at 33 m/s. The baseball will not gain acceleration in its flight. Therefore, its velocity is 33 m/s but its acceleration is 0.

But you throw a baseball straight up at 33 m/s. The initial velocity is 33 m/s . BUt gravity (acceleration) is pulling on the ball at -9.8m/s^2. SO at Time = 0, velocity is 33 m/s and acceleration = -9.8 m/s^2

The baseball will slow down as it goes up in the air (gravity is pulling on it making it come back down). Then it will accelerate towrds the earth, gaining speed until it either hits the earth or reaches terminal velocity.

9.8 m/s^2 is just a constant on earth because gravity is pulling on all obects (near the earth) with that much force.

Answer 2

Sounds like you have a falling object. No movement left or right and the acceleration due to gravity is 9.8 m/sec^2

Answer 3

The only acceleration you are dealing with in this case is gravity. If you choose your coordinate system with y vertical, and x horizontal; then since gravity is always straight down it is the y axis. Therefore, there is no acceleration horizontally (x axis).

There can be acceleration horizontally, just not gravity.