How do I check if an object's velocity changes to 0?

This local script is in starter character.

local Char = script.Parent

for _,v in pairs(Char:GetChildren())do
	if v:IsA("BasePart") then
		v.Touched:Connect(function()
			if Char.UpperTorso.Velocity.Y <= -100 then
				Char:FindFirstChild("Humanoid").Health = 0
			end
		end)
	end
end

How do I check if that velocity suddenly changes to 0 (as in the person has stopped falling)?

I think the best way to do this would be something like this

local loop = true
local vel
local pos1
local pos2

local function Check()
	pos1 = Char.UpperTorso.Position
	wait(.1)
	pos2 = Char.UpperTorso.Position
	repeat
		wait()
		if pos1 == pos2
			Char:WaitForChild('Humanoid').Health = 0
			loop = false
		else
			print('Still Falling') --Just to check if it's working. (The print function is good for checking if a function or something is working)
	until loop == false
end

for _,v in pairs(Char:GetChildren())do
    if v:IsA("BasePart") then
        v.Touched:Connect(Check)
    end
end

Don't know if it'll work. If it doesn't you get the idea of what i'm trying to do