How to detect player velocity when their state type is physics

I’m trying to make a particle effect come from the player when they’re sliding down a slope while their humanoidstatetype is physics, I have a variable that changes to true if it’s true and false if it’s false.

This is my code.

Root:GetPropertyChangedSignal("Velocity"):Connect(function()
	
	if physics == true then
		
		local v = Root.Velocity
		if v.Y < 0 then
			script.ParticlesEvent:FireServer(Character, physics)
		end
	end
			
end)