3D motion

Question 1

How is a vector described in 2D motion?

Answer 1

its defined by the sum of an x and y component, times their respected direction vector.

Question 2

how is a 3D vector described?

Answer 2

with an x, y and z component, times their respected direction vectors

Question 3

if a particle is thrown with constant speed in the postivie x-direction, in 2D, what does the y-axis contain?

Answer 3

The y-axis contains constant acceleration