Here's a breakdown:

* Gravity: This is the force that pulls everything towards the center of the Earth.

* Downward Direction: Gravity pulls objects in a straight line towards the center of the Earth, which we perceive as downwards.

However, the exact path of a falling particle can be influenced by several factors:

* Air Resistance: This force opposes the motion of the particle and can cause it to slow down or change direction slightly.

* Slope: If the ground is sloped, the particles will fall along the slope rather than straight down.

* Wind: Wind can push the particles sideways, affecting their fall trajectory.

Overall, the primary force governing the direction of falling soil and rock particles is gravity, which pulls them downwards.