How do i check if a player is falling for x amount of time?

Server script:

local firstpos
while wait() do
	for i,v in pairs(game.Workspace:GetChildren()) do
		if v:FindFirstChild("HumanoidRootPart") then
			if v.Humanoid.Sit == false then
			local person = v.HumanoidRootPart
			firstpos = person.Position
			wait(1)
			if (firstpos - person.Position).magnitude > 32 then
				print((firstpos - person.Position).magnitude)
				local player = game.Players:GetPlayerFromCharacter(person.Parent)
			player:Kick("silly u, im better")
				end
			end
			if v.Humanoid.Sit == true then
				local person = v.HumanoidRootPart
			firstpos = person.Position
			wait(1)
			if (firstpos - person.Position).magnitude > 166 then
				print((firstpos - person.Position).magnitude)
			local player = game.Players:GetPlayerFromCharacter(person.Parent)
			player:Kick("silly u, im better")
			end
			end
		end
		if v:FindFirstChild("Humanoid") then
			if v.Humanoid:GetState() == Enum.HumanoidStateType.Freefall then
				tick(3)
				print("fell for 3 sec")
			end
		end
	end
end

never used tick() but if i can remember it correctly from what i've seen its used to check something over time