BodyVelocity does absolutely nothing?

Hi. I was making a fireball script, but the BodyVelocity does not make the fireball move - it just sits there and doesn't move at all. Here is the full (but still being worked on) script:

local player = game.Players.LocalPlayer
local char = player.Character
local t = char.Torso
local mouse = player:GetMouse()

local RS = t["Right Shoulder"]
local LS = t["Left Shoulder"]
local RH = t["Right Hip"]
local LH = t["Left Hip"]

mouse.KeyDown:connect(function(key)
  if key:lower() == "f" then
    local fireb = Instance.new("Part", char.Torso)
    fireb.Anchored = true
    fireb.CanCollide = false
    fireb.Position = char.Torso.Position
    fireb.BrickColor = BrickColor.new("Deep orange")
    fireb.Transparency = 0.5
    fireb.Size = Vector3.new(4, 4, 4)
    fireb.CFrame = t.CFrame * CFrame.new(0, 0, -10)
    fireb.Shape = "Ball"
    fireb.TopSurface = "Smooth"
    fireb.BottomSurface = "Smooth"
    local b = Instance.new("BodyVelocity")
    b.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
    b.Velocity = char.Torso.CFrame.lookVector * 80
    b.Parent = fireb
    local fire = Instance.new("ParticleEmitter", fireb)
    fire.Color = ColorSequence.new(Color3.new(0.75, 0.75, 0))
    fire.Rate = 80
    fire.EmissionDirection = "Back"
    fire.Lifetime = NumberRange.new(2.5, 2.5)
    game:GetService("Debris"):AddItem(fireb, 5)
  end
end)