projectile motion

when we do projectile motion problems, we always break the motion into to components. x component and y component. for x component, the acceleration is always zero, in other words, no acceleration for x. for y component, the acceleration is the same as gravity which is 9.8m/s
 

there are 4 types of projectile motion:
-the first one is when someone throw something from the higher level to the horizon.



-the second one is someone throw something from the horizon to the horizon.


-the third one is someone throw something from the horizon to the higher level.

-the last one is someone throw something from the horizon to the lower level.