How can I cause a projectile to curve away from it's launched position?

Here is a more detailed question: "How can I cause a projectile to begin to curve, away from it's current launched position, shortly after being launched?"

local player = game.Players.LocalPlayer local bv = instance.new("BodyVelocity") 

local bav = instance.new("BodyAngularVelocity")

 local boom = game.Workspace:FindFirstChild("Boomerang") 

local m = player:GetMouse() 

m.Button1Down:connect(function(m)

 bv.Parent = boom 

bv.Velocity = player.Character.Head.CFrame.lookVector * 3

bv.MaxForce = Vector3.new(4.0000e+006, 6000, 4.0000e+006) 

wait(0.5)

bav.Parent = boom 

bav.AngularVelocity = Vector3.new (6, 0, 0) * math.rad(36) 

end)

This one is an attempted curve to the right. A curve for a ball, specifically. here is a link of what I'm going for (A football in this example) http://78.media.tumblr.com/0207afef34bdaf58ec039044ce6e0c9e/tumblr_ny7for3qMU1us21qco1_400.gif